Nedarim 89A

נדרה והיא ברשות הבעל ⁠— מפר לה. כיצד? אמרה ״הריני נזירה לאחר שלשים״, אף על פי שנתאלמנה או נתגרשה בתוך שלשים ⁠— הרי זה מופר. נדרה בו ביום ונתגרשה בו ביום, החזירה בו ביום ⁠— אינו יכול להפר. זה הכלל: כל שיצאה לרשות עצמה שעה אחת ⁠— אינו יכול להפר.

If she took a vow while she was under the jurisdiction of her husband, he can nullify the vow for her. How so? If she said when she was still married: I am hereby a nazirite for after 30 days, and her husband nullified the vow, then even if she was widowed or divorced within the 30-day period, the vow is nullified. If she took a vow on that, i.e., one, day and was divorced on that same day, then even if her husband took her back as his wife on that same day, he cannot nullify her previous vows. This is the principle: Once she has left and gone into her own jurisdiction for even a single hour, then after they are remarried her husband can no longer nullify any vow she uttered during their first marriage.

גמ׳ תניא: אלמנה וגרושה שאמרה ״הריני נזירה לכשאנשא״ ונשאת, רבי ישמעאל אומר: יפר, ורבי עקיבא אומר: לא יפר. וסימנא: יללי. אשת איש שאמרה ״הריני נזירה לכשאתגרש״ ונתגרשה, רבי ישמעאל אומר: לא יפר, ורבי עקיבא אומר: יפר.

Talmud: It is taught in a baraita: With regard to a widow or a divorcée who said: I am hereby a nazirite for when I will get married, and she was married, R' Yishmael says her husband can nullify her vow, whereas R' Akiva says he cannot nullify it. And the mnemonic device for the opinions of R' Yishmael and R' Akiva with regard to this halakha and the following one is the Hebrew acronym yod, lamed, lamed, yod: Yafer, lo yafer; lo yafer, yafer, i.e., he can nullify, he cannot nullify; he cannot nullify, he can nullify. As for a married woman who said while she was married: I am hereby a nazirite for when I will get divorced, and she was divorced, R' Yishmael says her husband cannot nullify her vow, whereas R' Akiva says he can nullify it.