Nedarim 8:7-9:1

Nedarim 8:7

If a person says to his friend, “Konam if I benefit from you, if you don’t come take a kor of wheat and two barrels of wine for your children,” the friend can void the person’s vow without him having to consult an authority by saying to him, “Didn’t you only say that for my honor? Well, me not taking those things is my honor.” If a person says to his friend, “Konam if you benefit from me, if you don’t come give my son a kor of wheat and two barrels of wine,” Rabbi Meir says the vow is in effect until the friend gives him those things but the Sages say that this person can also void the vow without consulting an authority by saying that it’s as if he received those things. If a man is being urged to marry his sister’s daughter and he says, “Konam that she ever benefit from me,” or if a man divorces his wife and says, “Konam if my wife ever benefit from me,” these women may derive benefit from him because his intention was only regarding the context of marriage. If a person is urging his friend to come for a meal and he says, “Konam I do not enter your house” or “I do not taste a cold drop of water from you,” he is permitted to enter his friend’s house and to drink his cold water because his intention was only in the context of a meal.

Nedarim 9:1

Rabbi Eliezer says that an opening to void a vow can be the honor of his parents, though the Sages prohibit this. Rabbi Tzadok says that rather than basing an opening on his parents’ honor, they should base it on God’s honor but if we did that, there would be no such thing as vows! The Sages do agree with Rabbi Eliezer that when a vow involves a person and his parents, then an opening to void it can be based on his parents’ honor.