Ketubot 71A

מעשה דבית חורון.

the incident of Beit Ḥoron, where an individual had vowed to prohibit his father from deriving benefit from him, and then in order to allow his father to come to the celebration of his son’s wedding, he gave all of his property to someone else as a gift. The recipient of the property was concerned that the vow would be transgressed by the father, so he consecrated the son’s property and declared that if he was not empowered to do so, then the original transfer of property as a gift would not be valid. Consequently, in the present case, the rabbis are unconcerned by the artifice performed, while R' Yosei is concerned with such artifice and therefore prohibits it.

רבי יהודה אומר: בישראל חדש אחד וכו׳. היינו תנא קמא? אמר אביי: כהנת אתא לאשמועינן. רבא אמר: חדש מלא וחדש חסר איכא בינייהו.

§ It was taught in the Mishnah: R' Yehuda says: If the husband is an Israelite, then if his vow will remain in effect for up to one month, he may maintain her as his wife; and if it will be two months, he must divorce her and give her the payment of her marriage contract. But if he is a priest, then he is given extra time: If the vow will remain in effect for up to two months, he may maintain her, and if it will be 3 months, he must divorce her and give her the payment of her marriage contract. The Talmud is puzzled by R' Yehuda’s statement with regard to an Israelite: This is the same as the opinion of the first tanna. Abaye said: Concerning an Israelite, R' Yehuda in fact does not disagree with the first tanna, but he comes to teach us that the halakha is different for the wife of a priest. Rava said: The practical difference between them is a full 30-day month and a deficient month with 29 days: The first tanna requires exactly 30 days, while R' Yehuda requires one month, whether it is a full month or a deficient one.