if he does not fulfill his obligation with it, for what purpose did the owner give it to him?

Rather, with regard to fulfilling his obligation, everyone agrees that he fulfills his obligation with it. It is only in a case where the first recipient sold it or consumed it, that we have arrived at the dispute between Rabbi Yehuda HaNasi and Rabban Shimon ben Gamliel. According to Rabbi Yehuda HaNasi, if he sold it, the second recipient can repossess the etrog from the purchaser, and if he consumed it he must pay the second recipient its value, whereas according to Rabban Shimon ben Gamliel, he owes nothing to the second recipient, as the etrog belongs to him.

Rabba bar Rav Huna says: In a case of brothers who acquired an etrog with money from the jointly held property of the estate, and one of them took it on Sukkot and attempted to fulfill his obligation with it, the halakha depends on the limits of his ownership of the etrog: If he may eat it, i.e., his brothers allow him to do so, he has fulfilled his obligation to perform the mitzva, and if not, he has not fulfilled his obligation.

And this is specifically in a case where there is an etrog for each and every one of the brothers; but if the other brothers get merely a quince or a pomegranate, he has not fulfilled his obligation even if he has the right to eat it.

Rava says: If one person said to another: This etrog is given to you as a gift on the condition that you return it to me, and the recipient took it on Sukkot and attempted to fulfill his obligation with it, if he ultimately returned it, he has fulfilled his obligation; if he did not return it, he has not fulfilled his obligation, as he did not fulfill the condition, thereby retroactively invalidating the gift. The Gemara explains that Rava teaches us that a gift given on the condition that it be returned is considered a valid gift.

§ The Gemara relates: There was a certain woman who had a palm tree on the land of Rav Beivai bar Abaye. Whenever she would go to harvest the produce from it, he would get angry at her for trampling on his crops. Since she did not wish to anger him, she decided to temporarily waive her right to the tree’s produce, and transferred ownership of it to him for all the years of his life, so that after his death she would once again be able to harvest the produce. He then went and transferred it to his minor son, so that it would remain in his family even following his death.

Rav Huna, son of Rav Yehoshua, said to Rav Beivai bar Abaye: Is it because you descend from truncated [mula’ei] people, as Rav Beivai’s family traced their lineage to Eli, all of whose descendants were condemned to premature death (see I Samuel 2:31), that you speak truncated [mulyata] and unsound matters? Even Rabban Shimon ben Gamliel, who holds that in a case where one says: My property is given to you, and after you, to so-and-so, if the first recipient sells the property the sale is valid, says so only in a case where it was to be given to another person; but if the giver said that it will return to himself, he did not say that the first recipient can sell it, as the giver clearly intended to maintain his ownership of the property. Accordingly, Rav Huna, son of Rav Yehoshua, held that Rav Beivai’s sale did not take effect.

§ Rava says that Rav Naḥman says: If one said to another: This ox is given to you as a gift on the condition that you return it to me, and the recipient consecrated it and then returned it to him, it is consecrated and returned. The consecration takes effect, and although the owner may not use it, nevertheless it is considered returned and the condition is fulfilled.

Rava said to Rav Naḥman: What did he return to him? The ox was not returned to the possession of the giver, as it is consecrated. Rav Naḥman said to him: And what did he cause him to lose? He returned the ox. Rather, Rav Ashi said: We must rule in this case based on what we see. If the giver said to the recipient: On the condition that you return it, it is considered returned, as he returned it. But if he said to him: On the condition that you return it to me, he was effectively saying to him that he must return something fit for him to use. Consequently, the consecration prevents the condition from being fulfilled, and both the gift and the consecration are retroactively nullified.

§ Rav Yehuda says that Shmuel says: If one writes a document granting his property to another, and the other person says: I do not want it, he acquires it, and this is the halakha even if he is standing and shouting in protest that he does not want it. And Rabbi Yoḥanan says that he does not acquire it.

Rabbi Abba bar Memel said: And they do not disagree with each other: