Chapter 100 of Tehillim is the familiar psalm known to all of us from the Shacharit prayer. Rashi explains: "A psalm for thanksgiving" - a psalm of praise, to be recited over the thanksgiving offerings (korban todah). That is, at the time when the thanksgiving sacrifice was brought, they would recite this psalm. Radak adds that we recite this psalm as an expression of gratitude to Hashem, blessed be He, and within it we call out to the entire world: "Shout joyfully to Hashem, all the earth."
מִזְמוֹר לְתוֹדָה הָרִיעוּ לַיהֹוָה כׇּל־הָאָרֶץ׃ - A psalm of thanksgiving: Shout joyfully to Hashem, all the earth.
This calls to mind what Chazal say regarding the thanksgiving offering (korban todah), that forty loaves of bread were brought along with it: thirty loaves of matzah and ten loaves of chametz. Moreover, all forty loaves had to be consumed that very same day; whatever remained became notar and had to be burned. How could one person finish forty loaves in a single day? Inevitably, he must invite friends, he throws a feast! Then people ask him: What happened? What is the celebration for? Since when do you throw parties? And he answers: You won't believe what a miracle occurred to me! Thus, by the very requirement of bringing forty loaves, the korban todah compels a person to gather people to eat, thereby obliging him to publicize the miracle.
This is precisely what Radak says here: "A psalm of thanksgiving" - and you shall say, "Shout joyfully to Hashem, all the earth." There is an essential purpose in publicizing the miracle. By gathering people and recounting it to them, one is telling them: Say, shout joyfully to Hashem, all the earth; let the entire world share in your rejoicing.
The Malbim explains that the concept of thanksgiving here refers to gratitude for a miracle. And what does "Shout joyfully to Hashem" mean? When the Holy One, blessed be He, conducts the world according to the laws of nature, He is, as it were, like an exalted king whose ministers, advisors, and officials govern the realm - this represents His providence through the heavenly bodies, the sun, moon, stars, rain, and natural order. But when the Holy One, blessed be He, directs the world through a miracle, He is compared to a king who steps out of his palace and leads the people himself, walking among them and personally overseeing all their affairs. And what happens when the king appears? Everyone immediately acclaims him: Long live the king!
This is why it is called "A psalm of thanksgiving." When Hashem, blessed be He, interacts with us through open, unveiled providence - through miraculous intervention - we all thank Him and shout in acclaim before Him. As scripture states, "All you nations, clap your hands; shout to God" - when the king walks among the people, they cheer for him, clap their hands, and offer thanks, praise, and glory.
One might add: When the Holy One, blessed be He, walks among the people, His kingship becomes plainly visible, and that is what inspires us to give thanks. For when does a person fail to thank Hashem? Consider this phenomenon: When someone talks about an accomplishment, he says, "Baruch Hashem, I worked hard, I did this, and Baruch Hashem it succeeded." In other words, he treats the Holy One, blessed be He, as a partner, a subtle kind of partnership worship: me and Hashem, with Heavenly assistance, Hashem gave me a hand. But when a person fails, suddenly "it is all from Heaven, it is all from Him, blessed be He," and he himself had no part in it. The successes are "mine, with Hashem giving a little push"; the failures have "nothing to do with me." When does a person truly say "A psalm of thanksgiving"? When he recognizes that everything is from Him, blessed be He. Therefore, "Shout joyfully to Hashem, all the earth" - for as the Malbim explains, this refers to a level of providence where Hashem is right beside us and His sovereignty is manifest, leaving no doubt as to who is responsible: the Master of the Universe.
A story is told of a man who asked an angel to give him a tour of Heaven. They arrived at one department where there was a tremendous commotion, faxes churning out pages, printers buzzing, angels scurrying about. He asked, "What is this place?" The angel replied, "This is the Petitions Department. Requests are pouring in constantly, and the angels have to process them, determining who receives what." They moved on to another department, and there too was loud commotion and intense activity. He asked, "What goes on here?" The angel said, "This is the Complaints Department. Faxes of complaints arrive non-stop, and they must figure out what to do with them." They continued walking until they reached a quiet, sleepy department where everyone was sitting and sipping tea, with all the time in the world. He asked, "And what is this department?" The angel replied, "This is the Thank-You Notes Department, the Department of Gratitude. Once every two hours, a single fax trickles in: 'Thank You, Master of the Universe, for helping me.'" When it comes to complaints, we are vigorous; when it comes to requests, we are relentless; but when it comes to thanksgiving - that is our Achilles' heel, that is where the difficulty lies. "A psalm of thanksgiving" - we must sing out in gratitude, "Shout joyfully to Hashem, all the earth," thanking Hashem for all the goodness He bestows upon us.
There is an explicit Halachah about this in the Shulchan Aruch (Orach Chaim 51:9): Mizmor LeSodah should be recited with a melody, for all songs are destined to cease in the future except for Mizmor LeSodah. This is an actual ruling, yet not many fulfill it, which is truly a pity. When reciting Mizmor LeSodah in the morning, one should not say it like the rest of Pesukei D'Zimrah - sing it, recite it with a tune. One does not have to sing loudly or use a specific melody, but it should be sung with a tune. Then the thanksgiving is genuinely evident, rather than being said merely to fulfill an obligation and get it over with.
There are times when Mizmor LeSodah is omitted, and here customs differ between communities. On Shabbat, everyone agrees that it is not recited, and the reason is simple: no Todah offering (korban todah) was brought on Shabbat. The same applies to Yom Tov, since the Todah offering is a voluntary offering (nedavah), and vows and voluntary offerings are not brought on Shabbat or Yom Tov, only obligatory communal offerings. On Pesach, some hold that it is omitted because the Todah offering includes ten loaves of chametz, and chametz cannot be brought on Pesach. Others say it should also not be recited on Erev Pesach, because one may not cause an offering to become disqualified and burnt, nor may one curtail its eating time: if brought on Erev Pesach, one would not be allowed to eat the chametz loaves after midday, thereby curtailing the allotted time for eating the Todah loaves. For this reason, some have the custom, especially among Ashkenazim, not to recite Mizmor LeSodah on the morning of the fourteenth of Nisan, as well as on Erev Yom Kippur. Sephardim, however, customarily recite it at all times except on Shabbat and Yom Tov.
Our Sages teach that the Todah offering will never cease. Likewise, Halachah will never cease - "This Torah shall not be replaced"; the Torah is eternal and enduring. Both concepts are hinted at in our verse: "Hari'u L'Hashem Kol Ha'aretz" (הריעו לה' כל הארץ) - the initial letters spell Halachah (הלכ"ה). And if we take the final letters - vav, hei, lamed, tzadi - their gematria equals "anavah" (ענווה, humility). As explained in Sefer Yosef Tehilot: Scripture comes to teach you that in order to merit reaching the true Halachah, one needs humility. One who possesses humility merits the Halachah.
Indeed, who was the individual through whom the entire Torah and all of Halachah were transmitted? The humblest of all men upon the face of the earth, Moshe Rabbeinu. A person with such self-nullification, with such humility, merits becoming the ultimate vessel for the Torah at the highest level. Similarly, the Gemara states regarding Beit Shammai and Beit Hillel: Why was the Halachah established according to Beit Hillel? Because they were gentle and modest, and they would teach the words of Beit Shammai before their own. Seemingly, what does character have to do with legal rulings? Had it said they were sharper, more exacting, and deeper analysts, we would understand. Rather, we learn from this that in order to align with the true Halachah, to arrive at the truth, one must be humble. So too it was said of King David that the Halachah always followed his opinion everywhere, and he was the one who said, "And I am a worm, and not a man."
Rav Ovadia Yosef once said to his son, Rav Yitzchak Yosef, regarding a certain rabbi who in several places in his responsa attacked the author of the Kaf HaChaim with harsh and even disparaging words: Look, that scholar was exceptionally sharp and accomplished, but today, who studies his works? Who even knows them? Yet the Kaf HaChaim was a profoundly humble man, and there were those who perhaps did not appreciate him enough - and see how well-known his works are, and how people quote "the Kaf HaChaim writes" on every subject. This teaches you: even if you disagree with the words of another Torah scholar, do not attack him, do not act demeaningly, and do not use harsh words. Such conduct only causes one's own Torah ultimately not to endure, while the one who acted with humility sees his Torah spread far and wide. We see from this that Halachah and humility are inextricably intertwined.
עִבְדוּ אֶת־יְהֹוָה בְּשִׂמְחָה בֹּאוּ לְפָנָיו בִּרְנָנָה׃ - Serve Hashem with joy; come before Him with singing.
דְּעוּ כִּי־יְהֹוָה הוּא אֱלֹהִים הוּא־עָשָׂנוּ וְלוֹ אֲנַחְנוּ עַמּוֹ וְצֹאן מַרְעִיתוֹ׃ - Know that Hashem, He is God; He made us, and we are His, His people and the sheep of His pasture.
Rashi asks: Why so much emphasis on serving Hashem with joy? The answer lies in the subsequent words - "for Hashem, He is God," meaning He is the One who pays the reward for your labor. When you know there is a reward for your labor, you serve with joy. Idolatrous worshippers, by contrast, have no reason to serve with joy, for they receive no reward - how could an idol pay a reward? How, then, could they serve with joy? The people of Israel, however, serve with joy, because we serve Hashem, who is God who rewards our actions.
From here we see a fundamental principle: when seeking to motivate people to action, one must speak of reward. Nor should we take this lightly, as if it were improper to speak of reward for mitzvot - after all, the Torah itself takes this approach. In Parashat Ki Tavo and Parashat Bechukotai, when the Torah speaks of blessings and curses, there is a "package of benefits," as well as the reverse. If you wish to inspire action, explain what will be gained and what benefit will come of it - that is what stirs a person to act. Therefore: serve Hashem with joy, for Hashem rewards your labor.
Ibn Ezra adds: "It is the way of every laborer to be sorrowful." The reality is that no one naturally enjoys toiling; everyone desires rest. One who works - particularly one forced to work - naturally tends toward gloom. Therefore it says, "Serve Hashem with gladness." Scripture does not stop there, but adds, "Come before His presence with singing" - so that the joy is not hidden and kept only within the heart, but is an outward, evident joy.
We find an expression of this in the Chafetz Chaim. He would conduct personal soul-searching, secluding himself to enumerate his shortcomings and missteps, speaking intimately with the Holy One, Blessed be He. People would occasionally stand outside and listen. Once, they overheard him rebuking and demanding of himself: "Yisrael Meir, perhaps you did not show enough joy in the service of Hashem; perhaps it was not clear enough from your performance of the mitzvos, Yisrael Meir, that the greatest joy is to serve the Master of the Universe!" It was not that the Chafetz Chaim lacked joy in fulfilling mitzvos; rather, he held himself accountable because perhaps it was not sufficiently noticeable on the outside, perhaps onlookers did not sense it. And this is precisely what Ibn Ezra means: True, serve Hashem with joy, but it must be outwardly visible - "Come before His presence with singing," so people can see that being a servant of Hashem is the greatest joy and the highest song.
Years ago, when Rabbi Uri Zohar published his first book, the cover featured photographs of chareidim, and they all shared one thing in common: joyful, smiling faces. He himself explained what brought him to do this. He had known a certain film director whom he had always dreaded working with: the man had a furrow between his eyes, something menacing, looking like someone who might explode at you at any moment. Later, he was told that this director had become a ba'al teshuvah. When he eventually met him, he was astonished to see that the furrow between his eyes had vanished. Suddenly he saw a calm, happy man, and his very countenance had changed. This is deeply fascinating, and it could be observed in Rabbi Uri Zohar himself: anyone who looks at photographs of him before his teshuvah sees fierce hardness in his face, yet looking at him afterward, one sees an unbelievable gentleness. He was one of those rare people who genuinely refined and corrected their character traits. A man who had sat at the height of secular fame, known as fierce and sharp-tongued, who never let anyone have the last word - say one word to him and you would receive four in return - and suddenly one saw such refinement, hearing the gentle way he spoke. Anyone who encountered him during those years, in his work for Lev L'Achim, witnessed how a person could transform himself and his very essence. This comes to teach us: serving Hashem and fulfilling the mitzvos refine a person, transform him, and make him truly happy. That is why he chose photographs of joyful people - see, my friend, keeping the mitzvos will bring you joy. "Come before His presence with singing" - and know that it will also show on the outside.
Radak explains: "Serve Hashem with gladness" - so that His service does not become a burden, but is done with joy and gladness of heart. This is a profound lesson, for on many occasions one can observe a person treating Torah and mitzvos as a heavy burden and a chore, something to just get out of the way. A person arrives at the synagogue for Shacharis and it weighs heavily upon him: he looks for ways to cut it short at the beginning, cut it short at the end, and even in the middle, messages are buzzing on his phone. Not only does he lack joyful song, but he also makes comments to the chazzan: "What happened to you, did you fall asleep? Don't you know a shorter Kedushah?" Constant complaints: "Let's finish this, let's wrap it up, enough, you've exhausted us!" And by contrast, who is the one who does not complain? The one who arrives half an hour before the tefillah begins and stays to learn for another half hour afterward; you can tell that prayer brings him joy, and he takes his time during the Shemoneh Esrei - his tefillah is as it should be.
The Rebbe of Gur once said: There are people who think, "We will suffer here in this world through the observance of mitzvos, and over there we will receive our reward." I am sorry to disappoint them: one does not receive reward for mitzvos that are endured as suffering. This does not refer to the principle that "one deed done with effort and pain is better than a hundred done without pain," for which one certainly receives a hundredfold reward; rather, it refers to a person whose entire attitude toward mitzvos is that of a burden and torment, as if the Holy One, Blessed be He, intended to punish him: "Here He punished me with Shacharis, and punished me with Minchah, and punished me with Torah study," so that everything feels like a punishment. Even if you do not say it aloud, it screams from within you. The urge to cut corners at every turn and shave off every halachah is an expression of saying, "Master of the Universe, You are punishing me, You are looking to harm me." Regarding this, the Holy One, Blessed be He, says: "Yet you have not called upon Me, O Yaakov, for you have grown weary of Me, O Yisrael" - when all My mitzvos weary you, you have the wrong address; you are not serving Me, but someone else. "The orders of Hashem are upright, rejoicing the heart" - if it does not bring you joy, you are evidently not in the right place and not connected to the true commandments. And how do you expect to receive reward for this? For the disparagement? For the contemptuous way you treated the mitzvos? For the fact that the Holy One, Blessed be He, seeks your good, yet you treat it as though He is out to harm you? How much mussar there is in this, for a person to ponder and reflect upon, so as to perform everything out of joy. To be sure, someone who is just starting out and finds it difficult is certainly not told to take on too much - slowly, step by step; whatever you do, be at peace with it and do it with joy. But to cast off the yoke and say, "It is too hard for me, so I am looking for ways to shake it off" - that is not the right path, and it is an attitude for which a person will ultimately be held to account.
And as for what we said regarding "one deed done with pain is better than a hundred done without pain," where one receives a hundredfold - that applies when a person finds it difficult to fulfill a mitzvah and nonetheless overcomes the challenge for the honor of the Creator. But when a person is not simply struggling, but looking to shed his obligations, and it all stems from contempt, of him it is said: "Yet you have not called upon Me, O Yaakov." However, if a person says: "It is hard for me, but because Hashem commanded it, I will exert myself and fulfill the will of the Holy One, Blessed be He, for the honor of the Creator" - for this he will receive a hundredfold reward.
The Midrash, cited by Radak, notes a contradiction: It is written, "Serve Hashem with awe" (Tehillim 2:11), and on the other hand it is written, "Serve Hashem with gladness." If with awe, how can it be with joy; and if with joy, how can it be with awe? Seemingly, these two are opposites: one who fears acts out of dread, while one who rejoices acts out of jubilation and gladness. Rabbi Aivu said: At the time you pray to the Holy One, Blessed be He, let your heart rejoice, for you are praying to the Holy One, Blessed be He, of Whom there is none like Him in all the world. Could it be without awe? Scripture teaches, "Serve Hashem with awe."
In other words, these are complementary dimensions. When I stand to pray before Hashem, I pray with joy - because I am praying to my Father in Heaven, "He did not do so for any nation." All the nations are like stepchildren before Him, whereas "You are children to Hashem your God" was addressed to only fifteen million people in all of creation - and I am among them; I have merited to be one of Hashem's children! And out of those fifteen million, perhaps three million truly know Hashem and serve Him properly, and I have merited to be counted among them out of eight billion human beings on earth. And the Holy One, Blessed be He, says to me: "I want an audience with you every single day." I am privileged to meet with the Master of the Universe day after day, to stand before Him and speak with Him like a child speaking to his father. For this, a person should be filled with immense joy! But on the other hand, someone standing before a king does not act foolishly; a person standing before a king does not suddenly answer a phone call - for such a thing, one could lose his head. Therefore, while we must indeed serve Hashem with joy, we also need awe: know before Whom you stand. These two do not contradict each other; they complete one another.
Rabbi Acha further said: "Serve Hashem with awe" in this world, but in the Future to Come, "trembling seized the hypocrites," and you will rejoice in the trembling that I will bring upon the nations of the world; hence, "Serve Hashem with gladness." That is, awe is for here in this world - a person needs yiras Shamayim here, as "God has acted so that they should fear Him." But in the Future to Come, it is specifically the hypocrites who will be gripped by terror, while you, who served Hashem with awe here, will rejoice at the trembling that will come upon the nations of the world. Thus, the complete fulfillment of "Serve Hashem with gladness" will be realized in the Future to Come.
There is another Midrash that says a person needs both joy and awe, or if you will, love and fear, and both traits are necessary. For when someone serves solely out of fear, no one likes being under pressure and no one likes being afraid, and that causes a person to look for ways to cast off the burden. Therefore, we are told: with love. And what does "with love" mean? Something I love, I do not look to shed; on the contrary, I want more and more of it.
On the other hand, if we settle for love alone, this too has a drawback: a lover often fails to show the proper respect. The simplest example: the sharpest words are said specifically to the people we love the most. You wouldn't say to your neighbor what you say to your wife. And why? Precisely because of the closeness, I feel free to speak my mind, whereas with someone I am not close to, even if he did something wrong, I feel uncomfortable rebuking him. The son of the Gadol HaDor speaks to him far more freely than you ever would, without a doubt. Closeness sometimes leads to a lack of deference, a feeling of "heimish," of being one of our own, and then one has no problem making remarks or even criticizing, whereas an outsider would certainly be cautious. So too, "like a son who acts petulantly before his father" - I set conditions for Him, "I am not leaving this circle until You bring rain" - and this comes precisely from an abundance of love. Therefore, awe (mora) is also needed. Awe creates distance: you are still speaking to the Master of the Universe; the Holy One, blessed be He, created you, and you are His creature. A son, yes, but one still needs to maintain a certain distance that instills reverence in your heart and makes it clear that you cannot be overly familiar. Love is necessary, but awe is what ensures that love does not lead a person to lose all sense of reverence, or perhaps even say things that are improper and unfitting.
The Malbim explains the difference between the service of Hashem and serving flesh and blood. One who serves flesh and blood finds no joy in his work, because a person naturally aspires to be independent. This is actually why the Holy One, blessed be He, created man with the obligation of mitzvos, since no one likes nahama d'chisufa (the bread of shame) - being dependent on another person, waiting for his paycheck while the boss is constantly watching on the security cameras to see how much I worked and who I talked to, and making critical remarks to boot. No one likes to be dependent on flesh and blood.
Furthermore, someone who works for flesh and blood is never guaranteed to be paid, and even if he is paid, the reward is not intrinsic to the work itself; he receives payment only at its conclusion. Consequently, a person labors with sadness. Why? Because whenever something is merely a means to an end, joy is experienced only at the finish line. For example, a person wants to earn a degree to start practicing medicine. He studies for seven years, and this is merely a path leading to the goal. Is he happy right now? Certainly not - he is sweating blood, perhaps cleaning stairwells to pay for his tuition. When will he experience joy? When he receives his degree, when the goal is achieved. One engaged merely in the means, says the Malbim, feels no joy while occupied with the means, but only when reaching the ultimate purpose.
Not so with the service of Hashem: it is itself both the reward and the ultimate purpose. Therefore: "Serve Hashem with gladness." When I perform a mitzvah right now, it is not "in order that...", but it is itself the ultimate purpose. I was placed here in this world to perform this mitzvah, and I am now fulfilling that very purpose - I am not merely on the way to the goal, nor is it merely a preparatory step (hechsher mitzvah).
In Christianity, people speak of the idea that the end justifies the means. There is an "important" goal, for instance, to promote "that man" (oto ha'ish), and if anyone stands in the way - Crusades, slaughtering everyone. And if someone interferes, one can fabricate false libels, blood libels, and whatever else. What didn't the Jews in Europe suffer when the goal was to promote that man, making all means permissible? In Judaism, there is no such concept at all. And why? Because in Judaism, every single means is an end in itself.
Let me explain: when I build a succah, it might seem that I am building it merely to sit in it on the first day, and that the construction is only a means to an end. But in reality, that is not the case, for the very act of building the succah is a mitzvah, and that itself is a goal. Consequently, one cannot say "the end justifies the means," because the means themselves are also an end. The toil in building the succah is the very substance of the goal, and one receives a reward for it, a great reward: it is written that when a person sweats while baking matzos or building a succah, the holy Arizal says that this effects atonement for blemishes to the covenant and more. Thus, the means leading to the goal are not merely a technical preparation to get there; they are an essential part of the goal itself. Everything leading to the purpose is itself a purpose and itself a mitzvah. Therefore, the notion that "the end justifies the means" does not apply - the means must be holy, for they are an end in their own right. And to summarize the words of the Malbim: in the service of Hashem, the mitzvah itself and the service of Hashem itself are the ultimate purpose, and therefore it must be done with joy.
And what is the meaning of "Come before Him with singing"? The Malbim explains: when a person comes before flesh and blood to ask for something, he weeps and pleads so that the other person will take pity on him and have mercy. When does he leave with singing? Only after the other party has agreed to fulfill his request. I came to the king with a petition, wept and begged, and finally he said: "Very well, I will sign for you, I grant your request" - and only then do I leave with joyful singing. In contrast, one who comes before Hashem comes with singing the moment he enters. That is why it says, "Come before Him with singing," and not "go" or "depart" - the verse is not speaking of the departure, but of the arrival itself, for the moment I come before Him, I am already filled with joyous song.
And if you ask: Is it guaranteed that Hashem will fulfill your request? In fact, according to Rabbi Yisrael Salanter, if a person trusts in Hashem with complete bitachon - indeed, he is guaranteed that Hashem will fulfill his request. To be sure, this is a matter of dispute already among the early authorities (Rishonim) and is not universally agreed upon, but this is the view of Rabbi Yisrael Salanter, and there are proofs for this position.
And even if you say that it is not guaranteed: people once prayed for one of the Gedolei Yisrael who had fallen ill. Prayers and public gatherings were held all over the world, but in the end he passed away. They approached the Brisker Rav and said, "Rebbe, we prayed and were not answered! Look at how many outcries and how many prayers were offered, yet we were not answered." He replied to them, "And who said you were not answered? You were answered - with a 'no.' 'No' is also an answer. Master of the Universe, heal him; Hashem says: 'No.' You received an answer, and the answer is no."
In other words, whatever Hashem's answer may be, I know that it is certainly good, for everything Hashem does leads to good. Therefore, even if I was told no - "Come before Him with joyful song," since a person must sing and thank Hashem for everything He gives, and also for what He does not give, because it is better for him not to have it. In my limited understanding, I think that things would be better if they happened this way, but Hashem says: "I understand better than you." After all, your young child wants popsicles, bubblegum, ice cream, and candies all day long, and we know that this is not good for him. And your child does not want to go to the dentist, yet we take him by force - why? Because we know it is good for him. If that is how we act toward our children, all the more so the Holy One, blessed be He, toward us. Therefore, whoever comes before Hashem should always come with joyous song, because with Hashem, even when the answer is "no," it is an answer, and I know that it is the best possible answer for me.
בֹּאוּ שְׁעָרָיו בְּתוֹדָה חֲצֵרֹתָיו בִּתְהִלָּה הוֹדוּ־לוֹ בָּרְכוּ שְׁמוֹ׃ - Enter His gates with thanksgiving, His courtyards with praise; give thanks to Him, bless His Name.
What is the meaning behind the repetition of thanksgiving (todah) and praise (tehillah)? The Malbim explains: Tehillah refers to the general deeds of Hashem, may He be blessed, whereas todah is specifically for what He has granted to me personally. For what He gave me, I give thanks; and for His encompassing deeds throughout the entire world, we praise Him. Similarly, this explains the distinction between "Give thanks to Him" (hodo lo) and "Bless His Name" (barchu shemo): thanksgiving is for personal kindness, while blessing refers to the overarching benevolence and abundance that the Holy One, blessed be He, bestows upon the world.
The Malbim adds: We cannot perceive the Holy One, blessed be He, in His essential Being; rather, we perceive His goodness - that which we receive from Him. We have discussed this several times, as well as in our study of the Kuzari: we have no grasp of His essence, and how do we come to know the Creator? Through what we receive from Him, like the parable of the King of India brought at length in the Kuzari. It emerges that we know the Holy One, blessed be He, through the abundance He bestows upon us; we perceive Him through His acts of goodness, and through this we give thanks, publicize, and praise His Name. This is why we say, "May the Name of Hashem be blessed" - why specifically "the Name of Hashem"? Because I cannot grasp Him in His essence, but only His "Name," His renown, as it were, while of His essential Being we have no comprehension at all.
Mizmor 100 is the psalm of thanksgiving: just as the thanksgiving offering (Korban Todah) requires its owner to gather people and publicize the miracle, so too the psalm proclaims, "Shout joyfully to Hashem, all the earth" - at a time when the Holy One, blessed be He, guides us with an overt, miraculous providence, like a king emerging from his palace to walk among his people. From here we see how weak we often are in thanksgiving compared to our requests and complaints; therefore, one should recite this psalm with melody and heartfelt gratitude. "Serve Hashem with joy" - because there is reward for our labor, because the service of Hashem is itself the ultimate purpose and not merely a means, and because it refines and brings joy to man; and "Come before Him with joyful song" - so that the joy is outwardly evident, and felt immediately as we come before Him, for whatever answer we receive is the very best for us. Alongside joy, reverence is also required, for love alone can lead to a lack of respect; and just as Halachah and humility are intertwined, so too joy and awe complement one another. And all our thanksgiving is for His benevolence, as it is only through His goodness that we can perceive Him - "May the Name of Hashem be blessed."