Bava Metzia, chapter 4, Mishnah 8. This Mishnah also continues the digression from the main topic of the chapter: in the previous Mishnah we listed five perutos - five areas in which the amount of a perutah determines the halachah. Now the Mishnah moves on to enumerate the five fifths: "Chamishah chumshin hen" - There are five fifths, meaning five areas in halachah where the law of an additional fifth goes into effect.
What is a chomesh:
A chomesh is an additional payment paid in various contexts when a person has acted improperly. Upon restitution, the person returns the original amount, called the principal, and adds a chomesh (a fifth) to it as a sort of fine or addition, and usually, there is also an element of atonement involved.
We must be precise about the meaning of the term: the chomesh is not a fifth of the principal, but an addition after which the chomesh constitutes a fifth of the total amount. A person who unintentionally ate four grapes of Terumah does not return just four, but adds a fifth grape - for every four, a fifth is added. Therefore, the most accurate translation of chomesh is an addition of twenty-five percent.
Structure of the Mishnah:
The structure of the Mishnah can be confusing, so let us set things straight. The Mishnah lists five categories, but the first category includes five different details, and the second category includes two details.
The first category - one who eats Terumah unintentionally:
A non-kohen who ate Terumah unintentionally is obligated to return the Terumah he ate. If Reuven ate the Terumah of Shimon the kohen, and he ate four grapes, he must return to Shimon the four grapes he took from him. Besides the monetary obligation, there is an obligation to return the Terumah itself, and the restitution is made with properly tithed non-sacred produce (chullin) - not with money, but with other grapes, tithed according to the law. Reuven gives them to Shimon, and from that moment on, they are treated with the sanctity of Terumah. In addition to this, he adds a fifth: if he ate four grapes, he returns five; if he drank four gallons of wine, he gives five gallons.
The prototype that appears in the verse is Terumah Gedolah - the first separation taken from the produce and given to the kohen, which must be treated with sanctity. Indeed, there is a dispute as to exactly which produce this obligation applies to, but certainly to wine, grain, and oil. In practice, however, there are four different halachic phenomena - four categories of food that are judged like Terumah Gedolah, because the Torah calls them Terumah in one place or another. The Mishnah lists five details: "Ha'ochel Terumah, uTerumas ma'aser, uTerumas ma'aser shel demai, hachallah, vehabikkurim" - One who eats Terumah, Terumas ma'aser, Terumas ma'aser of demai, challah, and bikkurim:
Terumah Gedolah - The first separation from the produce given to the kohen.
Terumas ma'aser - Ten percent taken from the first tithe (ma'aser rishon) received by the Levite, meaning the tithe from the tithe.
Terumas ma'aser of demai - A completely separate matter, which will be explained below.
Challah - The portion of dough given to the kohen, which the Torah calls Terumah.
Bikkurim - The first fruits of the seven species growing in the Land of Israel, which must be brought up to Jerusalem and waved with the kohen, and the kohen receives them. They too are called Terumah in another place.
Regarding Terumas ma'aser of demai: demai is produce bought from an am ha'aretz (an unlearned person). During the time of the Mishnah, the assumption was that the amei ha'aretz tithed most of their fruits properly, and almost all of them certainly separated Terumah Gedolah properly. However, a significant minority did not give the tithe to the Levite, and furthermore, they reasoned that since they had not separated a tithe, there is no obligation for Terumas ma'aser. Consequently, the Terumas ma'aser remains hidden within the food bought from the am ha'aretz, and since there is no certainty that it was tithed properly, it is called demai, which literally means "da mai" - what is this. Therefore, a non-kohen who eats demai before separating from it is concerned about the Terumas ma'aser within it (but there is no concern about Terumah Gedolah, since the amei ha'aretz are careful with it), and therefore he must return what he ate with the addition of a fifth.
Since these four things are called Terumah, there is one law for all of them in this context: a non-kohen who eats them unintentionally violates a prohibition, the punishment for which is death at the hands of Heaven, a premature death, but this can be rectified by returning what he took, with the addition of a fifth, and with repentance.
The Second Category - One Who Redeems His Neta Revai and Maaser Sheni:
The language of the Mishnah: "VeHapodeh neta revai umaaser sheni shelo" - and one who redeems his neta revai and maaser sheni. The primary case is maaser sheni. The obligation to separate it applies in the first, second, fourth, and fifth years of the Shemitah cycle: after separating terumah gedolah and maaser rishon for the kohen and the Levi, the owner separates ten percent of the remainder and brings it up to Jerusalem to eat it there. He has the option to redeem the sanctity of the maaser sheni onto coins, if he is unable to bring up the produce or the load is heavy, and he brings the coins up to Jerusalem and buys food with them.
One who redeems his produce onto coins adds a fifth to the value of the coins. For example, a person holding a ten shekel coin that he will bring up to Jerusalem, and he has maaser sheni olive oil worth eight shekels that he does not want to carry: he redeems the sanctity of the oil onto the coin, and thus the full capacity of the ten shekel coin is utilized - eight shekels against the oil, and another two fifths (a fifth for every four) that complete it to nine and to ten. It turns out that he must bring to Jerusalem a value twenty-five percent greater than what he had in his house.
This law applies only to one who redeems his own produce. One who redeems the produce of another, meaning he buys the maaser sheni from him - he gives him the money, and the other gives the maaser sheni, and the proceeds of the sale become sanctified with the sanctity of maaser sheni, and with it the seller will go up to Jerusalem to buy his food. In this case, there is no fifth added at all.
From here to neta revai, the produce of the fourth year. In the first three years, the produce is orlah and forbidden to be eaten. In the fourth year (without getting into the method of calculating the years), the produce is no longer forbidden, but rather must be eaten in Jerusalem according to the law of revai, and its law is exactly like the law of maaser sheni. This comparison is learned from a gezeirah shavah of "kodesh kodesh" in the verses: one who redeems his revai produce onto coins designated for Jerusalem - adds a fifth. Someone who had revai grapes worth four shekels will use a five shekel coin, and its value is fully utilized.
It is worth noting that there is a way to avoid adding the fifth: two people can make an exchange transaction between them - this one sells his grapes to that one and that one sells his grapes to this one, and each one redeems onto his coins produce that is not his. Since the fifth applies only when one redeems revai or maaser sheni produce that is his own, they are thereby exempt from the fifth.
The Third Category - One Who Redeems His Hekdesh:
The language of the Mishnah: "Hapodeh et hekdesho, mosif chomesh" - one who redeems his hekdesh adds a fifth. A person may consecrate to bedek habayit anything he wishes. If he consecrated an object - the Temple sells it, the object becomes chullin and transfers to the ownership of the buyer, and the money becomes sanctified and serves the Temple for all its needs. However, if the one who consecrated it retracts and wishes to redeem his hekdesh, for instance if he realizes he needs the object, and prefers to give its monetary value to the Temple and save it the trouble of selling - he is obligated to add a fifth. If the market value of the object is one hundred shekels, he gives hekdesh one hundred and twenty-five.
The Fourth Category - One Who Derives Benefit From Hekdesh:
The language of the Mishnah: "Haneheneh beshaveh perutah min hahekdesh, mosif chomesh" - one who derives a perutah's worth of benefit from hekdesh adds a fifth. We dealt with the laws of meilah in the previous mishnah: one who unwittingly benefits from hekdesh property has violated a prohibition and committed meilah. He must bring an asham meilos sacrifice, and additionally pay for what he benefited from, since through his use he profaned it, and add a fifth. If he used a consecrated sheep - its milk or its wool - and the value of the benefit is one hundred, he returns one hundred and twenty-five. All of this is when the benefit is a perutah's worth or more; for less than a perutah's worth, the Mishnah says, this law does not take effect.
The Fifth Category - One Who Robs and Swears Falsely:
The language of the Mishnah: "Vehagozel et chaveiro shaveh perutah venishba lo, mosif chomesh" - and one who robs his fellow of a perutah's worth and swears to him adds a fifth. We touched upon this as well in the previous mishnah: a person who owes money to his fellow, and when the other demanded it he swore a complete oath that he does not owe him, and afterwards comes to repent and admits that he indeed owed it - he must return the money, something incumbent upon him anyway by virtue of "you shall surely return it" and due to the negative commandment against robbery, and beyond that to add twenty-five percent, which is the fifth.
Let us clarify this with an example. One who forcibly robs his fellow of four hundred shekels is obligated to return only four hundred. A thief who is caught pays double - eight hundred. But if he lied and swore falsely, and subsequently confessed, then one who admits to what he owes is exempt from the double payment, however, due to the law of the fifth he must return the four hundred with the addition of a fifth - five hundred. Likewise, he must bring a special korban for the false oath. Furthermore: he must personally transport the five hundred shekels and his korban to the owner, even if he has to travel to the ends of the earth or to the desert.
In summary: The Mishnah enumerates five areas in which the law of the fifth applies - an addition of twenty-five percent to the principal: The first is a non-kohen who inadvertently eats Terumah, Terumas maaser, Terumas maaser of demai, challah, or bikkurim, whose restitution is made with properly tithed chullin with the addition of a fifth; the second is one who redeems his neta revai and his maaser sheni, and specifically his own; the third is one who redeems his hekdesh; the fourth is one who inadvertently derives a perutah's worth of benefit from hekdesh, who brings an asham me'ilos and repays with the addition of a fifth; and the fifth is one who robs his fellow of a perutah's worth, swears falsely to him, and subsequently confesses - who returns the principal with the addition of a fifth, brings a korban, and transports the payment to the owner himself.