Talmud - Bava Metzia 44b בבא מציעא מ״ד ב׳

which circulate, in the sense that they are universally accepted by merchants, in contrast to gold coins, which merchants are less willing to accept as payment for inexpensive items, are currency; gold coins, which do not circulate, are a commodity. And the principle is: When one party takes possession of the commodity, the other party acquires the currency.

Rav Ashi said: It is reasonable to teach the halakha in accordance with that which he taught in his youth. This is from the fact that the tanna teaches later in the mishna: When one party takes possession of the copper coins, the other party acquires the silver coins.

Rav Ashi explains: Granted, if you say that the silver coins relative to the gold coins are a commodity, that is the reason that the tanna teaches: When one party takes possession of the copper coins, the other party acquires the silver coins, as, even though relative to the gold coins, the silver coins are a commodity, the tanna teaches that relative to copper coins, they are currency. But if you say that the silver coins relative to the gold coins are currency the subsequent ruling is self-evident, as now, relative to the gold coins, which are more valuable than the silver coins, you say that silver coins are currency, then relative to copper coins, as the silver coins are more valuable than the copper coins and they also circulate more easily, is it necessary for the mishna to state that the silver coins are currency and the copper coins are a commodity?

The Gemara rejects this proof. Even if you teach the halakha in accordance with the opinion of Rabbi Yehuda HaNasi in his old age, it was necessary for the tanna to teach the halakha of silver and copper coins as well. This is because it might enter your mind to say that in a place where these copper perutot circulate, they circulate more easily than silver coins. Therefore, say that they are the currency and the silver coins are the commodity. Therefore, the tanna teaches us that since silver coins are universally accepted as currency and there is a place where copper coins do not circulate, the copper coins are a commodity.

§ The Gemara comments: And Rabbi Ḥiyya, as well, holds that gold coins are currency relative to silver. This is seen from the incident where Rav borrowed gold dinars from the daughter of Rabbi Ḥiyya. Ultimately, the gold dinars appreciated in value. Rav came before Rabbi Ḥiyya to ask his opinion. Rav was concerned that by returning more valuable dinars than he borrowed, this would violate the prohibition against paying interest. Rabbi Ḥiyya said to Rav: Go and pay her unflawed and weighed dinars. Return the number of dinars that you borrowed, as their monetary value is irrelevant. The Gemara asks: Granted, if you say that the gold coins are currency, this works out well, as he borrowed and repaid the same coins. But if you say that the gold coins are a commodity, this is parallel to the case of one who borrows a se’a of produce and repays a se’a of produce, which is prohibited, as the price of the produce may increase in the interim (see 75a).

The Gemara rejects this proof. The dinars that Rav received from the daughter of Rabbi Ḥiyya did not constitute a standard loan, as Rav had dinars elsewhere, but he needed money immediately. And since he had dinars, it is tantamount to saying to her: Lend me money until my son comes or until I find the key. As the mishna on 75a teaches, when the borrower possesses the same item he is borrowing, and merely does not have momentary access to it, this type of borrowing and repayment is permitted.

Rava said: This following tanna also holds that the gold coins are currency, as it is taught in a baraita: The peruta of which the Sages spoke in all places in the mishna is one-eighth of an Italian issar. The Gemara asks: What is the practical difference that emerges from this calculation? Ostensibly, a peruta is a peruta. The Gemara explains: Its consequences are for the betrothal of a woman with money, which can be effected only with money or an item worth at least one peruta. This peruta is assessed by means of the Italian issar. The baraita continues: An issar is one twenty-fourth of a silver dinar. The Gemara asks: What is the practical difference that emerges from this calculation? The Gemara answers: Its consequences are for buying and selling, to establish its value for use in commercial transactions.

The baraita continues: A silver dinar is one twenty-fifth of a gold dinar. What is the practical difference that emerges from this calculation? The Gemara explains: Its consequences are with regard to redemption of the firstborn son. The father of a firstborn gives the priest five sela, which are worth twenty silver dinars. Were he to give the priest a gold dinar he would receive five silver dinars change.

The Gemara asks: Granted, if you say that the gold coins are currency, the tanna calculates the value of the coins based on an item whose value is fixed. The value of the gold coin is the currency with fixed value, relative to which the silver dinar is a commodity, whose value fluctuates. But if you say that gold is a commodity, would the tanna calculate the value of a silver coin based on an item that appreciates and depreciates? If the value of gold fluctuates, sometimes the priest returns more than five silver dinars to the father who redeemed his son with a gold dinar, and sometimes the father must add to the gold dinar and give this additional sum along with the gold dinar to the priest to complete the sum of five sela. Rather, learn from it that the tanna holds that the gold coins are currency. The Gemara affirms: Learn from it that this is so.

§ We learned in a mishna there (Ma’aser Sheni 2:7): Beit Shammai say: A person may not transfer silver sela coins of tithe money or other consecrated coins into gold dinars through redemption, and Beit Hillel permit doing so. Rabbi Yoḥanan and Reish Lakish disagreed. One said: The dispute between Beit Shammai and Beit Hillel is with regard to exchanging silver sela coins for gold dinars, as Beit Shammai hold that the silver coins are currency and the gold coins are a commodity, and we do not desacralize currency with a commodity. And Beit Hillel hold that the silver coins are a commodity and the gold coins are currency, and we desacralize a commodity with currency. But everyone agrees that we desacralize produce with gold dinars.

What is the reason for the difference between sela coins and produce? The reason is just as it is with regard to silver coins according to Beit Hillel. With regard to silver coins according to Beit Hillel, although silver coins relative to gold coins are a commodity, relative to produce they are currency. So too is the status of gold coins according to Beit Shammai: Although gold coins are a commodity relative to silver coins, relative to produce they are currency. Therefore, one may desacralize produce with gold dinars. And one said: Even with regard to the exchange of produce for dinars there is a dispute between Beit Shammai and Beit Hillel.

The Gemara asks: And according to the one who says: There is a dispute even with regard to the exchange of produce for dinars, then rather than disagreeing with regard to the exchange of sela coins for dinars let them disagree with regard to the fundamental case of desacralizing, the exchange of produce for dinars. The Gemara answers: Had they disagreed with regard to the exchange of produce for dinars, I would say: This matter applies only with regard to the exchange of produce for dinars. But with regard to the exchange of sela coins for dinars, Beit Hillel concede to Beit Shammai that gold coins relative to silver coins are a commodity, and we do not desacralize currency with a commodity. Therefore, the tanna teaches us that they disagree in that case as well.

The Gemara suggests: Conclude that in this dispute between Rabbi Yoḥanan and Reish Lakish it is Rabbi Yoḥanan who said: One does not desacralize produce with gold dinars, as Rabbi Yoḥanan said:

Traduction : The William Davidson digital edition of the Koren Noé Talmud, with commentary by Rabbi Adin Even-Israel Steinsaltz.

Bava Metzia 44b explores how coins of gold, silver, and copper are ranked as currency versus commodity in transactions of acquisition.