“these,” comes to teach that this halakha applies only to the animals given as payment to the prostitute but not to their offspring. The Gemara asks: And from where do Beit Hillel derive this halakha? They would say that one should conclude two conclusions from this term: “These” items are disqualified, but not when they are in their changed form, and “these” are disqualified, but not their offspring. The Gemara asks: And according to the opinion of Beit Hillel, isn’t it written “even”? Since Beit Hillel reject the halakha that Beit Shammai derive from this term, what do they learn from it? The Gemara states: Indeed, the word “even” is difficult according to the opinion of Beit Hillel.

In any event, they disagree only with regard to this particular issue: One Sage, Beit Hillel, holds that a physical change in a stolen item causes the thief to acquire it, and one Sage, Beit Shammai, holds that a physical change in a stolen item does not cause the thief to acquire it. But with regard to the payment of the thief, everyone agrees that he pays according to the initial value of the item, at the time of the theft, as it teaches in the baraita cited above: He pays the double payment and the fourfold or fivefold payment according to the animal’s value as of the time when he stole it.

The Gemara suggests: Shall we say that this baraita constitutes a conclusive refutation of the opinion of Rav? As Rav says: When a thief makes his payments, he pays the principal according to the value as of the time when he stole it, whereas the double payment and the fourfold or fivefold payment are calculated according to the value at the time of standing trial. Rava said in resolution of this difficulty: If one stole lambs that subsequently became rams or were fattened, he pays the double payment and the fourfold or fivefold payment according to the initial state of the animal, as claimed by both Beit Shammai and Beit Hillel. If there was a change in the animal’s value due to fluctuation of the monetary value of animals, he pays according to the animal’s worth now, at the time of standing trial.

§ Rabba said: The principle that a change in a stolen item causes the thief to acquire it is written in the Torah, and we learned it in a mishna as well. It is written in the Torah: “Then it shall be, if he has sinned, and is guilty, that he shall restore the item that he robbed” (Leviticus 5:23). What is the meaning when the verse states the seemingly superfluous phrase “that he robbed”? This serves to teach that if the item is the same as it was when he stole it, he must return the stolen item itself. But if it is not the same as it was then, he is required to pay only money, while the stolen item remains his to keep.

We learned this halakha in a mishna as well, as it is taught (93b): In the case of one who robs another of wood and fashions it into vessels, or one who robs another of wool and fashions it into garments, he pays the robbery victim according to the value of the goods at the time of the robbery, and keeps the altered materials for himself.

Alternatively, another mishna can serve as the source for this principle (Ḥullin 135a): If one did not manage to give the first of the sheared wool of his sheep to a priest until after he dyed it (see Deuteronomy 18:4), he is exempt from giving it to the priest. This mishna indicates that an item that has undergone a change is no longer considered the same item as it had been. Apparently, a physical change in a stolen item causes the thief to acquire it.

§ Rabba continues to discuss the ways in which a thief acquires ownership of a stolen item: With regard to the owner’s despair over ever recovering the stolen item, the Sages say that this too causes the thief to acquire the stolen item. However, we do not know if this halakha applies by Torah law or by rabbinic law.

Rabba elaborates on the two possibilities he has just mentioned: If it applies by Torah law, this is just as it is with regard to one who finds a lost item. Is it not the case with regard to one who finds a lost item that once the owner of the item despairs of recovering it, before the item came into the finder’s possession, the finder acquires it and may keep it for himself? The same principle applies to this thief as well: Once the owner of the item despairs of recovering it, the thief acquires it for himself and need no longer return it. Apparently, then, the despair of the owner causes the thief to acquire the stolen item.

Or perhaps the case of a stolen item is not comparable to the case of a lost item, as it is only with regard to a lost item that the owner’s despair enables the finder to acquire the item, because the item came into his possession in a permitted manner. But in this case of the thief, since the item came into his possession in a prohibited manner, this case cannot be derived from the halakha of a lost item. If so, the ruling that despair effects acquisition in a case of theft applies not by Torah law but by rabbinic law.

Why would this halakha have been instituted by rabbinic law? As, the Sages said that a thief should acquire the stolen item in this manner, due to an ordinance instituted for the penitent. To encourage thieves to repent and repay their victims, the Sages instituted that they need not return the stolen item after the owner despairs of recovering it. Rather, they can reimburse the owner for the monetary value of the item.

And Rav Yosef says: Despair on the part of the owner over the possibility of recovering his item does not cause the thief to acquire that item at all, and this is the halakha even by rabbinic law.

Rav Yosef raised an objection to Rabba from a mishna (96b): If one robbed another of leavened bread and Passover elapsed in the meantime, so that deriving benefit from it is prohibited,