Introduction
Psalm 84 is a psalm of yearning for the House of Hashem. The psalm is divided into three parts, and as we have already seen, every place where the word "Selah" appears marks the conclusion of a section. Up to the verse "Fortunate are those who dwell in Your house; they will continually praise You, Selah," the first part concluded, and from there the second part begins. Here we will address verses 5 - 7, which explain who these fortunate ones are, and what that paved highway in the heart truly is.
אַשְׁרֵי יוֹשְׁבֵי בֵיתֶךָ עוֹד יְהַלְלוּךָ סֶּלָה׃ - "Fortunate are those who dwell in Your house; they will continually praise You, Selah."
One Who Enters Shuls in This World - Enters in the World to Come
In the sefer Tehillos Maharit, Rav Dushinsky explains the verse based on the Midrash: Rabbi Yehoshua ben Levi said that whoever enters shuls and batei midrash in this world merits to enter shuls and batei midrash in the World to Come. It is not certain that we fully grasp how earth-shattering this statement is. There are people who enter the shul and immediately look to run; a shiur begins - and they flee. Such a person is a great expert in the laws of tircha detzibbura (burdening the congregation) in all their details and clauses: "Nu, Rabbi, you are holding up the tzibbur!" To the laws of Torah study he has not yet managed to arrive, but in tircha detzibbura he is remarkably proficient. These are people who look to flee from the House of Hashem. Regarding such an attitude, Scripture already states that one who turns his ear away from hearing Torah - even his prayer is an abomination. One could say to him: It is a pity you are standing here to pray. The very foundation is to hear Torah.
These matters are staggering: A person arrives in the World to Come; there is a shul there - "May I enter?" No, sir. For sixty years you had a shul next to your house and you did not enter it, so here too, you may not enter. "A beis midrash - may I enter?" Stay outside. You had a beis midrash, you never went to a shiur, you never came to learn - you cannot enter. This is a terrifying judgment.
Spend Much Time in Study and Seek Mercy - Torah and Prayer
According to this, the Maharit explains, one can understand the words of the Gemara in Niddah (70b): What should a person do to become wise? Let him spend much time in the house of study (yeshiva). They said to him: Many have done so, and it did not help them. Rather, let him pray for mercy from the One to Whom wisdom belongs. First and foremost - one must delve extensively into Torah study. There are no shortcuts and no "instant" solutions; to grow wise in Torah, one must learn. But there are many who learned for years and did not achieve it, and therefore prayer is also needed - to plead before the One to Whom wisdom belongs. The very effort to attain wisdom is immensely important, but it is not enough without siyata diShemaya (Heavenly assistance).
This is the precise wording of the Midrash: "shuls and batei midrash" - note the duality. In their times, there was a clear distinction: a beis midrash was exclusively for study, and a shul was exclusively for prayer. The Midrash tells you: you need both. You must pray to the One to Whom wisdom belongs, and you must also spend much time in study. If you pray all day to the One to Whom wisdom belongs but do not learn - what will it accomplish? What do you expect, that they will download the Torah into your brain via USB? It does not work that way. Therefore, one who arrives early at the shul and offers his prayer there that he succeed in his studies, and from there proceeds to the beis midrash to engage in study - this will enable him to merit entering shuls and batei midrash in the World to Come, and to bask in the radiance of the Shechinah, for he will indeed acquire Torah properly as is fitting.
This is reminiscent of what is recounted regarding Rabbi Isser Zalman Meltzer and other Torah giants, who testified about themselves that on any day they did not concentrate properly in Ahavas Olam (or in the Ashkenazi nusach, Ahavah Rabbah) - on the words "and put into our hearts understanding to comprehend and to discern, to hear, to learn, and to teach" - they would not merit to formulate novel Torah insights. Consider what this means - it is a wondrous thing! We are speaking of a giant of the spirit with a brilliant mind. Yet novel Torah insights are not merely a function of intellect; it is not simply the speed of one's processor. It is siyata diShemaya, and siyata diShemaya is acquired through prayer. This is what Rabbi Yehoshua ben Levi meant: whoever enters shuls and batei midrash - which encompasses both prayer and Torah - will merit "Fortunate are those who dwell in Your house; they will continually praise You, Selah," so that in the Future to Come as well, he will enter shuls and batei midrash.
"They Will Yet Praise You" - In This World as Well
Furthermore, this applies not only to the Future to Come, but often in this world as well. There are people whom one invites to a shiur, and they put it off: "When I am older," "When I retire." And then the person grows old and retires - and you cannot see him from a mile away. Perhaps he even desires it intensely, but it is no longer entirely within his control. The reality is that one who comes to learn Torah in his youth will also come in his old age; and for one who did not come in his youth and wishes to begin in his old age - this is not to say it is impossible, but it is exceedingly difficult. Therefore, a person must realize: go while you are young, utilize your strength now, and then you will continue coming even after retirement. But if in your youth you flee from the beis midrash, do not assume that in your old age it will come naturally - you will either show up and fall asleep, or you will flee, saying: "This is too burdensome for me; it's not for me." Why? Because you are not accustomed to it. This, then, is an additional insight: whoever enters shuls and batei midrash when he is young - will merit to enter them when he is older as well, fulfilling "they will yet praise You, Selah."
"Yoshvei" - An Expression of Lingering
The Tehillot Mahari"tz further explains that "yoshev" often does not mean sitting, but rather lingering or staying, as in the verse, "וַנֵּשֶׁב בְּקָדֵשׁ יָמִים רַבִּים" ("And we stayed in Kadesh many days") - did they never stand there? Rather, "to sit" means to linger. And "Your house" refers to synagogues and study halls, which are called the House of Hashem. Praiseworthy are those who linger in the House of Hashem. That is to say: a person has already arrived to pray, has already come to a shiur. There are those who wait constantly for it to end so they can run off, and regarding them Chazal said, "like a schoolchild fleeing from school." But there are others who say: "I will linger a little longer, study a little Chok LeYisrael, learn a Mishnah." This does not refer to someone pressed for time who barely managed to come and must leave, but rather to ordinary days when one has time, or certainly on Shabbat, when there is usually leisure. Concerning those who linger, it is said, "They will yet praise You, selah" - they continue and increase their praise and thanks to Hashem, and they will merit "selah," forever, even in the World to Come, to thank and praise the blessed Name.
A thought was once offered on the saying, "There is one who acquires his world in a single hour": an avrech who sits and learns - praiseworthy is he and praiseworthy is his portion; this is a great virtue, achieved amid hardship and scarcity. Yet often, when the hour arrives after which there is no further stipend, people pack up and rush home. But one can say: there is one who acquires his world in a single hour! Stay another ten minutes, stay another quarter of an hour - you acquire your world. As Rav Ovadia Yosef once remarked about a teacher who came to teach schoolchildren in a Talmud Torah but had no heart for teaching, applying the verse, "and with two he flies" - waiting for two o'clock to arrive so he could fly away and escape. This is not the proper path. A person should not treat Torah, mitzvot, and the service of Hashem as a burden to be cast off, like a schoolchild fleeing from school. The primary reward is given for lingering just a little longer, and that is precisely why it is the hardest thing - because it goes beyond what one is used to and beyond what one is obligated to do. And for what goes beyond, the Holy One, blessed be He, gives beyond: salvations beyond what a person naturally deserves. You did a little more, and Hashem says: "I will give you more than you deserve."
Someone once recounted that he prolonged his Arvit prayer, and the gabbai turned off the lights and shut the door - almost locking him inside, unable to understand what he was still doing there. The response was: a synagogue is meant for prayer, in case you did not know.
אַשְׁרֵי אָדָם עוֹז־לוֹ בָךְ מְסִלּוֹת בִּלְבָבָם׃ - Praiseworthy is the person whose strength is in You, highways are in their hearts.
Precision in Reading
Here too, there are two common mistakes. First, "עוֹז לוֹ בָךְ" (oz lo vach) - and not becha. Second, "מְסִלּוֹת" (mesilot) - the lamed has a dagesh, and it is not read with a long chirik as mesilot without a dagesh. One must understand that not every detail pointed out here necessarily alters the meaning; even if one reads "yoshvei veitecha" with one musical stress or another, he has still recited Ashrei. Yet reading with grammatical precision means knowing the correct vocalization and proper reading. There are situations where it does matter, though most of the grammatical notes mentioned here do not change the meaning of the words.
Rashi: Highways of Uprightness
Rashi explains: "Praiseworthy is the person whose strength is in You" - praiseworthy is one who makes You the stronghold of his trust, for You are the stronghold of his trust and he trusts in You. "Highways are in their hearts" - he calculates in his heart the highways of his ways to straighten his path. In his heart, he possesses paved highways according to which he walks uprightly. In contrast, there is a person whose heart is crooked, lacking a paved, straight highway in his heart: even when a direct door is open, he looks for a back door. This is a person who constantly searches for schemes and roundabout ways. It is like the joke about a man who needs a vaccination and turns to a community activist in shul: "Tell me, do you have connections at Magen David Adom?" My friend, what connections do you need? Pick up the phone, walk into MDA, and get your shot! There are people for whom nothing ever goes straight; they are always looking for someone with connections or a cousin in the right department. Why? There is a straight path. This is "highways are in their hearts." And how does one merit walking on a straight path? One whose "strength is in You" - whoever trusts in Hashem walks on the straight path, whereas one who lacks trust believes he must resort to crooked efforts and cunning schemes. If you have trust in Hashem, walk on the straight path, and Hashem will provide what is due to you.
Radak: A Highway Born of Knowing Hashem
Radak explains in the name of his father: "Praiseworthy is the person whose strength is in You" - one who possesses strength and wisdom in the knowledge of Your oneness, which is the root of serving You, as it is written, "Know the God of your father and serve Him." Praiseworthy is the person who knows the Holy One, blessed be He, recognizes His oneness, and serves Him. "Highways are in their hearts" - through knowledge of You, they possess paved highways in their hearts; they travel back and forth along these highways, growing in courage each day. That is to say, whoever possesses knowledge of Hashem has a paved path in his service in this world. Who is the one who constantly veers this way and slips that way? The one who lacks knowledge of Hashem; when there is no paved road, one slips off in different directions every time. But whoever has a highway in his heart walks straight upon it, without doubts and without stumbling.
This connects directly to what was seen earlier: "Praiseworthy are those who dwell in Your house." Those who dwell in Your house are the ones whose strength is in You, because they seclude themselves in the House of Hashem, engage in wisdom, and exert themselves to know Hashem. Such a person truly possesses a highway in his heart. In contrast, one who does not come to the House of Hashem, does not attend Torah classes, and does not cleave to Hashem, blessed be He, is plagued by doubts and indecision: whether to do this or that, whom to trust and whom not to trust. But the one who dwells in the House of Hashem and the beit midrash knows the source of truth, and walks along a straight, paved path without hesitation.
Ibn Ezra: The Strength of the Pilgrims
Ibn Ezra explains the verse as referring to the pilgrims: fortunate are those among the Jewish people who celebrate and make the pilgrimage to rejoice in the House of Hashem - and they need strength (oz), for the pilgrimage was no simple feat. It was not like today, where you get into a car or board an airplane and arrive immediately; in their day, it was a major undertaking that demanded great fortitude. "Highways in their heart" - he has no other occupation or thought; his entire heart is devoted to the path. He is completely focused on his journey to the House of Hashem.
The Malbim: A Paved Highway in the Heart Amid Exile
The Malbim explains that here begins the second part of the psalm: even though we cannot currently ascend to the House of Hashem in practice, and we find ourselves in the reality of exile - nevertheless, "fortunate is the man whose strength is in You," for he anticipates Hashem's redemption with inner strength and possesses complete trust that Hashem will redeem us with an everlasting redemption. "Highways in their heart" - in their hearts there is a paved highway along which they will, as it were, return to Zion. Even though the highway does not physically exist and the Beit HaMikdash has not yet been rebuilt, in his heart the highway is already there; the place is already prepared where he envisions the path by which he walks to the House of Hashem. Simply put, it is already in his heart, in his spiritual consciousness; he lives it. This is similar to what we find regarding the arrival of Mashiach: there were gedolim who, if told "he is coming," would leap up immediately, certain that Mashiach had arrived, because they were waiting and poised for his coming. The Chafetz Chaim prepared a special suit for the arrival of Mashiach. Why? Because he lived it; there was already a highway in his heart leading there. But for someone who did not prepare, it will come as a complete surprise.
The Maggid of Mezritch: Strength - But "in You"
The Maggid of Mezritch says: Chazal expounded that "oz" refers to Torah, as in "Hashem will give strength (oz) to His people." Now, there can be a person who has strength - he has Torah - but not "in You." An example of this is Korach, of whom it is written that he was a talmid chacham: "And Korach took," and Chazal taught that "taking" refers to nothing other than Torah, as it is said, "For I have given you a good doctrine (lekach)." Korach indeed took Torah, but not with the Holy One, blessed be He - he had strength, but not in You. So too with Doeg HaEdomi: he had strength, but not in You; he mastered three hundred halachot regarding a tower floating in the air, and more. He was a man of immense strength and immense Torah knowledge, yet completely disconnected from the Holy One, blessed be He. Fortunate is the person who has strength and Torah - but "in You."
And as the Baal Shem Tov explains the statement of Chazal, "One who reviews his chapter one hundred times is not comparable to one who reviews his chapter one hundred and one times": what difference does one hundred or one hundred and one really make? Rather, "and one" (ve'achat) alludes to "the One" (ve'Echad) - the One, our God in heaven and on earth. One who reviews one hundred times represents Korach: he may review a hundred times, but he is missing "the One"; he is not with the Holy One, blessed be He. By contrast, one who reviews his chapter one hundred times and One does so together with the One Who encompasses all of reality; his Torah stems from yirat Shamayim and a desire to fulfill the mitzvot. He is not studying academic Torah like a university student of Talmudic studies; rather, he learns Torah that transforms a person and makes him a better, more upright individual, both toward his fellow man and toward Heaven. This is "strength is his" - but "in You," together with the Holy One, blessed be He, and not on his own.
Complete Bitachon - While the Pathways Are Still Open
The Tehillot Maharit brings a homily of Chazal: "'Fortunate is the man whose strength is in You' - could this mean for anyone? The verse teaches, 'Highways in their heart.'" This is an enigmatic Midrash, and he explains it as follows: there are people who turn to the Master of the Universe only when they reach the brink of the abyss, after a series of medical treatments when the doctor tells them there is nothing left to do. Only then do they say, "Now, only prayers can help." In other words, only after reaching total crisis do you seek out the Holy One, blessed be He. That is a very meager, pitiable bitachon; it can hardly be called trust in Hashem. It is the reaction of someone who has tried everything else, and now tries the Holy One, blessed be He, as well. Genuine, complete bitachon is when all options lie open before me and I say: Master of the Universe, I set all of this aside and trust in You; You will help me.
This is what the verse means: "'Fortunate is the man whose strength is in You' - could this apply to everyone, whether one at the beginning of the road or one who has already tried every option without success? It says: no." Fortunate are specifically those who have "highways in their heart" - the person of complete trust, who has open pathways and viable options before him, and nevertheless says: Master of the Universe, I leave it all and lean upon You. But for someone who has no choice left, where the doctor has thrown up his hands and material options no longer exist, and only then casts himself upon the Holy One, blessed be He - there are no longer any open pathways. There is no great achievement in turning to Hashem only when every other door has been shut. How wonderful a thought.
The Sign That Torah Was Absorbed - Pathways in the Heart
The Tehillot Maharit further explains in light of the Mishnah in Avot: "Turn it over and turn it over, for everything is in it, and you have no finer measure than it." That is to say, as long as a person does not see blessing in his study, it is proof that he has not yet studied it properly - "If someone says, 'I labored and did not find,' do not believe him." Torah study inevitably leads a person to good character traits and upright conduct, and that is the true sign that his learning was successful and that he studied properly. Therefore: "Fortunate is the man whose strength is in You" - when? When you see "highways in their heart," meaning that the Torah has directed him onto the straight path, and the person is upright in his deeds, upright in matters between man and God and upright between man and his fellow. One for whom the Torah has carved highways in his heart and who is truly straightened out - of him I know that "strength is his in You," that his Torah is connected to You. But if not, this is not Torah study as Hashem commanded, for you see that he has not changed and that his learning has had no effect upon him.
עֹבְרֵי בְּעֵמֶק הַבָּכָא מַעְיָן יְשִׁיתוּהוּ גַּם־בְּרָכוֹת יַעְטֶה מוֹרֶה׃ - Passing through the valley of weeping, they make it a spring; the early rain also covers it with blessings.
Precision in the Reading
Here too, we should take note of the grammatical nuance. It is ovrei and not oivrei - the sheva here is a vocal sheva (sheva na). Likewise, ma'yan and not ma'ayan: the mem has a patach, and a patach is a short vowel, and there is no meteg or dagesh here to vocalize the ayin; therefore the ayin is quiescent, and the sheva is a silent sheva (sheva nach). So too, ya'teh and not ya'ateh.
Rashi: Emek HaBacha - Gehinnom
Rashi explains: "Those who pass through" (ovrei) refers to those who transgress (ovrim) the Torah of Hashem, and they find themselves in Emek HaBacha, in Gehinnom, in the valley of weeping (bechi). Gan Eden is considered an exalted place on high, while the wicked descend below; Chazal tell us that the location of Gehinnom is beneath the surface of the earth, and the Gemara points out a site where smoke billows out as one of the gates to Gehinnom. All the expressions used for Gehinnom denote descent - "they deepen Gehinnom for them" - even though at its core it is a spiritual realm. "They make it a spring" - through the sheer volume of their tears, they turn that valley into a flowing spring. "The teacher is also wrapped in blessings" - they bless and give thanks to His Name, declaring: You have judged us truthfully, You have judged us justly; and may blessings envelop the one who taught us to walk on the good path, even though we did not listen to him.
A profound lesson emerges from here: even if you rebuked someone and he responds by insulting and reviling you, know that after a hundred and twenty years, when he passes through the valley of weeping, he will say: May blessings rest upon that person who rebuked me; I deserve the punishment for not listening to him. Today he may curse you - do not worry, there he will yet bless you: How noble was that person who came and rebuked me, offering words of mussar, and how foolish was I for refusing to heed and listen.
Radak: The Springs of Wisdom
Radak, who explained the preceding pesukim as referring to the Kohanim and the pious - "Happy are they who dwell in Your house, they will yet praise You, selah" - explains here as well that the words are spoken metaphorically regarding the wise. Here, bacha is related to "the springs of the sea" (nivchei yam), the place from which the sea flows forth. They traverse the valley of the springs of wisdom, the vast sea of knowledge. We see that the quality of water serves as a metaphor for knowledge and positive influence; similarly, Torah is compared to water that descends to a low place - for one who conducts himself with humility and lowliness, the Torah descends to dwell with him. "They make it a spring" - they turn it into a spring for those who come after them, teaching wisdom to their students and passing it forward, so that the disciples may drink from the waters of wisdom and come to know Hashem, rather than drinking from contaminated waters - once again we see that even corrupt philosophy is termed drinking, except that one drinks from bitter, poisonous waters. "The teacher is also wrapped in blessings" - blessings will cloak the one who instructs the students in the ways of wisdom, like one who blesses whoever guides his disciples along the path of Hashem.
Malbim: The Highways Pass Through Babylon
Malbim continues along his consistent path: those very highways in their hearts are "passing through the valley of the bacha trees." Babylon was a low-lying valley, which is why it was called Shinar - for it was there that the dead of the Flood were cast off (nin'aru), because it was so low; everything that floated during the Flood gradually drifted down with the waters to the lowest place, to Babylon. And it was filled with trees, as it is written: "By the rivers of Babylon... upon the willows in its midst we hung our harps." Here the psalmist employs the term bachaim instead of willows, in the sense of "when you hear the sound of marching in the tops of the bacha trees" - which are also a species of tree. Why did he prefer the term bachaim? Because it also hints at weeping (bechi), a play on words to capture their anguish in exile: "There we sat and also wept." Thus, the highways in their hearts pass through the bacha trees, and with weeping they will journey toward God in Zion. Their hearts envision that they are walking on highways through the bacha trees toward Zion - this is their constant yearning to return to the Land of Israel, to reach the rebuilt Beis HaMikdash, and to cherish its dust.
"They make it a spring" - those highways in their hearts, which express the longing for Zion, render their heart like a flowing spring; a spring is the emblem of an ever-flowing source brimming with bounty and blessing, like an surging spring within their heart. "The early rain also covers it with blessings" - the blessings that envelope the heart through these visions and through its trust are in the category of moreh, in the sense of early rain (yoreh umalkosh). For in the water cycle, rain rises from below: from the spring mists ascend, form clouds, and from them rain descends. In this way, that spring within their heart raises up clouds and brings down a rain of blessing and generosity - meaning, their influence is not confined to themselves alone. The longing of "when will we finally arrive, when will a highway to Jerusalem be built" impacts the collective, awakening in others as well a deep yearning and desire to reach Jerusalem. This is just as we find with Elkanah, who, on every annual pilgrimage, would ascend from a different direction along a different route, in order to inspire and encourage the public to make the pilgrimage and come to the House of Hashem in Shiloh. It turns out that the influence of a person who yearns and strives for the rebuilding of the Beis HaMikdash, in whose heart the highway is already paved, is like rain that bestows and showers blessing and bounty upon others.
The Sfas Emes: An Inner Spring Even in a Lowly Place
The Sfas Emes explains that the verse refers back to those who have paved highways in their hearts: when Torah is inscribed and engraved upon a person's heart, even when he passes through the Valley of Bacha - a place far removed from holiness, say, if he has to pass through the central bus station in Tel Aviv - even there, "they make it a spring." He possesses an internal flowing spring that detaches him from all his surroundings and from the place in which he finds himself. That is to say, someone who is properly built spiritually, in terms of Torah study and his cleaving to Hashem, blessed be He, even if circumstances cast him into lowly places that are hardly environments for serving Hashem - since his path is already paved, even there he radiates goodness, and even there he elevates himself in the service of Hashem.
However, one who was unstable to begin with - as the Chazon Ish once said. They asked him how it could be that the Holocaust strengthened some people to the point that they reached very high levels of faith and divine service specifically in its wake, while others shattered to pieces. He told them: know that the Holocaust was an enormous upheaval. It is like a parable of two barrels: one has sugar settled at the bottom, and the other has mud at the bottom. As long as you do not shake them, both appear clear at the top, and you see neither the sugar nor the mud. But stir them: the one with the sugar - suddenly you taste that it is sweet; and the one with the mud - now the filth is exposed. Those who fell apart during the Holocaust were people for whom the mitzvos were burdensome to begin with; they were always looking to be rid of them, seeking shortcuts and looking to do as little as possible. When the Holocaust came, there was already an excuse: "This is what the Holy One, blessed be He, does to us? That is it, I am leaving everything behind." But those who have paved highways in their hearts, as the Sfas Emes says, whose path of Hashem is already paved in their heart and who serve Hashem with joy - when trouble strikes or the unexpected happens, "Hashem is righteous, for His word is true," they justify Heaven's decree upon themselves and accept it with love, knowing that everything is for the good and that this is a process through which the Holy One, blessed be He, is putting them through a trial. But one who has no paved highways in his heart to begin with - when he is brought to a place with a few problems and a bit of a challenge, he shatters into pieces and falls.
Rav Mazuz: Allusions in "HaBacha"
Rav Mazuz, may Hashem send him a complete recovery, amen, notes that the spelling is "HaBacha" (הבכא) with an alef and not "הבכה" with a hei. He cites the Gemara's homily in Eruvin 19a: "'Emek' [valley] - for Gehinnom is deepened for them." He suggests an allusion: "HaBacha" (הבכא) is an acronym for "Hushlachta bimtzulot k'mo even" (You were cast into the depths like a stone) - those who pass through Gehinnom are cast into the depths like a stone. And incidentally, one of the names of the evil inclination is "stone," and one might say: you followed the stone - "And I will remove the heart of stone" - and therefore you are cast into the depths of Gehinnom like a stone.
He adds that through letter substitution, it can be read as "HaBacha" (הבכה) with a hei, which is an acronym for "Ha-holchim b'derech kol ha-aretz" (Those who go the way of all the earth) - this is not a verse, but refers to a person who has passed away; specifically those deceased who, Heaven protect us, are in Kaf HaKela (the hollow of the sling). Furthermore, what was said earlier, "cast into the depths like a stone," is akin to Kaf HaKela, of which it is written that it is like a stone slung from a sling. Kaf HaKela is not just a metaphor for Gehinnom - it is a sling: a type of pouch in which a slingstone is placed, whirled around, and hurled; anyone who has ever seen stones hurled understands what this means.
And by what grammatical rule do the letters alef and hei interchange? Letters from the same phonetic family interchange with one another - dalet, tet, lamed, nun, tav interchange; beit, vav, mem, pei interchange; meaning one may use one letter in place of another when they share the same point of articulation. For instance, among the labials (bumaf), a beit can be used in place of a pei, as is found in biblical Hebrew orthography. Here too, alef and hei belong to the guttural letters (ahacha), and therefore they interchange.
In summary:
The three verses construct a single progression: "Praiseworthy are those who dwell in Your house" - praiseworthy is one who lingers in the House of Hashem, joining prayer to Torah, synagogues to study halls, and therefore will merit entering them in the World to Come as well as throughout his life here. "Praiseworthy is the person whose strength is in You, with highways in their hearts" - praiseworthy is one whose Torah is bound to the Holy One, blessed be He, who trusts in Hashem out of choice rather than lack of alternative, and whose heart the Torah has smoothed into a highway of uprightness; and according to the Malbim, praiseworthy is one in whose heart the highway to Zion is already paved even amidst exile. "Passing through the Valley of Bacha, they make it a spring" - that very heart turns even the arid valley into a flowing spring, bestowing blessing upon himself and upon others like an early rain that descends, holding steadfast in every place and through every upheaval. And this is the ultimate test of a person: if Torah has carved paved highways within him, it is a sign that his strength is truly "in You."