(Mishnah): If Reuven vowed before Shemitah (the seventh year, in which whatever grows is Hefker) 'Shimon may not benefit from me', Shimon may not enter Reuven's field, nor eat from trees whose foliage extends past Reuven's property;

In Shemitah, he may not enter the field, but he may eat from what hangs outside.

If Reuven vowed before Shemitah 'Shimon may not eat from me', Shimon may enter Reuven's field, but he may not eat from what hangs outside;

In Shemitah, he may enter the field and eat.

(Gemara - Rav and Shmuel): If Reuven vowed before Shemitah 'this property (Tosfos' text - of mine) is forbidden to you', Shimon may not enter Reuven's field, nor eat from what hangs outside, even in Shemitah;

If he vowed during Shemitah, Shimon may not enter the field, but he may eat from what hangs outside.

(R. Yochanan and Reish Lakish): If he vowed before Shemitah 'my property is forbidden to you', Shimon may not enter his field, nor eat from what hangs outside;

When Shemitah comes, he still may not enter the field, but he may eat from what hangs outside.

Suggestion #1: Rav and Shmuel hold that a person can forbid something in his possession, and it remains forbidden even after it leaves his possession. R. Yochanan and Reish Lakish hold that when it leaves his possession, it is permitted.

Objection #1: It is unreasonable that anyone would say that a person cannot forbid property even after it leaves him!

If so, they should have argued when he says 'this property', and all the more so, they will argue about when he says 'my property'!

Objection #2: A Mishnah teaches that one can forbid property even after it leaves him!

(Mishnah): If Reuven told his son 'you may not benefit from me', when Reuven dies, his son inherits him;

If he said 'You may not benefit from me in my life nor after my death', his son does not inherit him. (I.e. he inherits him, but may not benefit from it.)

Answer (to Objection #2): That case is different, for he said 'in my life and after my death'.

Objection #1 still stands.

Suggestion #2: Rather, all agree that when a person says 'this property', he forbids it even after it leaves his possession. They argue about when he says 'my property';

Rav and Shmuel say that in either case, the property remains forbidden;

R. Yochanan and Reish Lakish hold that if he said 'my property', it becomes permitted after it leaves him.

Objection: Does anyone really hold that even if he said 'my property', it remains forbidden?!

(Mishnah): If Levi told David 'I will not enter your house or buy your field', and David died or sold them, they are permitted;

If he said 'I will not enter this house or buy this field' and David died or sold them, they are forbidden.

Conclusion: Rather, R. Yochanan and Reish Lakish teach about when he says 'my property.' Rav and Shmuel teach about when he says 'this property'. They do not argue.

(Mishnah): In Shemitah he may not enter his field...

Question: He may eat from what hangs outside because it is ownerless (in Shemitah). For the same reason, he should be allowed to enter the land!

Answer #1 (Ula): The case is, the trees are on the border (and the fruit can be taken without entering the field).

Answer #2 (R. Shimon ben Elyakim): This is a decree, lest he tarry on the field longer than necessary to take the fruit.

(Mishnah): If Reuven was Mudar Hana'ah from Shimon, Reuven may not lend to or borrow from Shimon objects or money. He may not buy from him or sell to him.