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Hilchos Nedarim 12:16
When Numbers 30:15 says, “from one day to the next,” it means that if a woman makes a vow at night, her father or husband can annul it during the night and throughout the following day, as we discussed. If she made a vow and her father or husband only heard of it after several days, he can annul it on the day he hears of it. This is considered as if she had vowed on the day that he heard of it, as per Numbers 30:6, “On the day he heard of it,” rather than just on the day that she made the vow.
Hilchos Nedarim 12:17
Let’s say that a betrothed naarah (“maiden”) made a vow and her father heard of it and annulled it. A few days later, her fiancé hears of it and annuls it on that day. In such a case, her vow is not annulled, based on Numbers 30:6-8: “If her father restrained her on the day he heard of it... If she was married (betrothed) to a man with her vows upon her... and her husband hears of it, on the day he hears of it....” Since her father annulled the vow and her fiancé heard of it, he must annul it on the same day that the father heard of it. Similarly, if her fiancé heard and annulled it and, several days later, the father hears of the vow and annuls it, it is not annulled. We know that this verse refers a betrothed naarah because Numbers 30:11-12 says, “If she vows in her husband’s home... and her husband hears and remains silent to her.” We see that the latter case is after the marriage has been completed, so the husband referred to in the previous scenario must refer to a woman’s fiancé.