We read the following in a mishnah two days ago:
One who says to another: “Entering your house is forbidden for me,” or, “Purchasing your field is forbidden for me,” — if the owner dies or sells to another, it is permitted to him.
But if he said: “Entering this house is forbidden for me,” or, “Purchasing this field is forbidden for me,” then even if the owner dies or sells it to another, it is forbidden to him.
The mishnah’s conclusions are intuitive: If the vow regards a specific person’s house or field, then it is in effect only as long as that person actually owns the house or field. If that ownership ends, through death or sale, then the vow is no longer in effect. However, if the vow is made with regard to the house or field itself and without reference to the owner, then the vow stands even if the owner dies or sells.
On the top of today’s daf, the Gemara asks a related question:
Avimi raises a dilemma: If the owner of a house said: “Entering this house is forbidden for you,” and then he died or sold it to another, what is the halakhah? Do we say that a person can render an item in his possession forbidden even for a time after it will leave his possession, or not?
Now the vow has shifted. Instead of Reuven vowing not to benefit from Shimon, Shimon has vowed that Reuven cannot benefit from him. Avimi wants to know if Shimon’s vow continues to have a hold, even when the house and field no longer belong to him. Can Shimon keep Reuven off his property even when the property no longer belongs to him?
The Gemara brings another mishnah to shed light on this question:
Rava said: Come and hear a proof from another mishnah (Bava Kamma 108b–109a): “If one says to his son, ‘Benefiting from me is forbidden for you,’ and dies, the son still inherits from him. If, however, the father explicitly states that benefit is forbidden both in his lifetime and after his death, and dies, the son does not inherit from him.” Conclude from this that a person can render an item in his possession forbidden even for a time after it will leave his possession.
The answer to Avimi’s question seems to be yes: The second mishnah shows that a person can make a vow about something they own that continues to hold even after they no longer own it.
We have seen throughout this tractate that the rabbis would prefer to minimize vowing among Jews because of the concern that people will create opportunities for sin by making vows and then forgetting their terms. This mishnah imported from Bava Kamma highlights another danger of vows: The possibility of using them in a moment of anger to do enormous damage — for instance, to disinherit a child. Another reason, perhaps, the rabbis preferred that Jews simply avoid the practice altogether.
Read all of Nedarim 47 on Sefaria.
This piece originally appeared in a My Jewish Learning Daf Yomi email newsletter sent on December 11th, 2022. If you are interested in receiving the newsletter, sign up here.