- If the first recipient can sell the property in the case of נכסי לך ואחריך לפלוני
A Baraisa teaches that if one says: "נכסי לך ואחריך לפלוני" – “My properties are yours, and after you die, they go to Ploni,” and the first recipient sold the property, Rebbe says: השני מוציא מיד הלקוחות – the second recipient can take the properties from the buyers, because the sale is void. Rabban Shimon ben Gamliel says: אין לשני אלא מה ששייר ראשון – the second recipient has nothing but what the first recipient left for him. The sale is valid, and nothing is left for the second person. According to Rebbe Yochanan, these Tannaim argue about whether or not קנין פירות is equal to קנין הגוף, which would enable the first recipient to sell the property. According to Reish Lakish, both Tannaim agree with him that קנין פירות is not כקנין הגוף. Rabban Shimon holds אחריך שאני – the case of “after you” is different, because it implies that he completely gives the property itself to the first recipient, and after him, to the second. A contradictory statement from Rabban Shimon proves that he agrees the first recipient is not permitted to sell the property, although the sale is effective. Abaye says the term "רשע ערום" – cunning wicked person refers to one who advises the first recipient to sell the property.
- מתנת שכיב מרע takes effect after death, not at the time of death
Rebbe Yochanan says the halachah follows Rabban Shimon ben Gamliel (that the first recipient’s sale is valid in the case of "אחריך לפלוני"), but Rabban Shimon agrees that if he gave it away as a מתנת שכיב מרע – gift of a gravely ill person, it is not effective. Abaye explained: מתנת שכיב מרע לא קנה אלא לאחר מיתה – a שכיב מרע’s gift only takes effect after his death, וכבר קדמו אחריך – and by then, the “after you” [second recipient] already preceded him by acquiring it when the first recipient died.
The Gemara objects that Abaye contradicts himself, because in a discussion about when a מתנת שכיב מרע takes effect, Abaye said: עם גמר מיתה – with the conclusion of his death (i.e., when he dies), and Rava says after he dies!? The Gemara answers that Abaye retracted his opinion and agreed with Rava. This can be proven from a Mishnah, which teaches that when a get is made dependent on the husband’s death, it is invalid, since it cannot take effect until after he dies.
- מתנה על מנת להחזיר, where he was makdish the gift and then returned it
Rava says that if one says, “This אתרוג is given to you as a gift, על מנת שתחזירהו לי – on condition that you return it to me,” and the recipient performed the mitzvah with it, then if he returned it, he fulfills his mitzvah. This is because מתנה על מנת להחזיר שמה מתנה – a gift given on condition to be returned is considered a gift, and it is “his” אתרוג. Rava quoted Rav Nachman saying that if one gave another a שור on condition that he returns it, and the recipient was makdish it and then returned it, הרי זה מוקדש ומוחזר – it is both consecrated and returned. Its being made hekdesh does not detract from his returning it. Rava asked Rav Nachman: מאי אהדריה – but what did he return to him? He cannot use it! Rav Nachman replied: ומאי חסריה – what has he removed from him? The ox was physically returned! The Gemara concludes that if he said, “on condition that you return it,” this returning is sufficient, but if he said, “on condition you return it to me,” מידי דחזי ליה קאמר ליה – he was telling him to return something useful to him.