The Mishna on our daf teaches that there is a difference of opinion in a case where a woman takes a neder that she will not perform those activities that a woman is obligated to perform for her husband based on their agreement in the ketuba (see Massekhet Ketubot 59 for a list of these activities).
- The Tanna Kamma rules that there is no need for hafara since there is an existing obligation that she cannot shirk simply because of her neder.
- Rabbi Akiva rules that he must be mefer the neder, since we fear that she may do more than she is obligated to do.
- Rabbi Yohanan ben Nuri also feels that there must be hafara, arguing that if he does not do so, then in the event of divorce she will become forbidden to him.
The approach taken by most of the rishonim is based on the Gemara in Ketubot (66a), which explains that the disagreement among the tannaim is centered around the question of who “owns” the wife’s work that is done over-and-above the basic requirement.
- According to the Tanna Kamma, all of her efforts belong to her husband, so there is no concern that he will get more than he deserves. Therefore there is no need for hafara.
- According to Rabbi Akiva, the extra effort belongs to the woman. He is, therefore, concerned that she will do more than she is obligated to do and that her husband will receive benefits that are forbidden to him. Therefore he requires the husband to annul the vow.
- Rabbi Yohanan ben Nuri essentially agrees with the Tanna Kamma, but he raises a different concern – unless the vow is annulled, once the marriage is over the neder will come into play and any and all of her efforts will be forbidden to her husband.
The Ran in Ketubot asks why we should be at all concerned with what may happen at some point in the future. The general approach to this obvious question is that we are concerned that leaving such a vow active will limit the possibility that the couple can remarry in the event of a divorce.