Nedarim 9:8-9

Nedarim 9:8

If one says, “Konam that I do not taste wine because it’s bad for the digestion” and he was then informed that aged wine is in fact good for digestion, his vow is not only voided for aged wine but for all wine. If he said, “Konam that I do not taste onions because they’re bad for the heart” and he is then informed that a certain species of onion (“kufri”) is in fact good for the heart, his vow is not only voided for that species of onion but for all onions. This actually happened and Rabbi Meir permitted all types of onions to the one who had vowed.

Nedarim 9:9

An opening to annul a vow can be made for a man based on his own honor and that of his children. They ask him, “Would you have vowed if you had known that the next day people would be talking about you, saying how you divorce your wives, and disparaging your daughters by suggesting that their mother did something unseemly?” If he says, “Had I known, I would not have vowed,” then his vow is annulled.