2,791. Misinformation

Hilchos Nedarim 8:6

If part of a vow is permitted, the whole thing is permitted; the same is true when it comes to oaths. For example, let’s say that someone saw from a distance that people were eating his figs, so he declared them to be like a sacrifice to those people. When he drew near, he saw that they were his father and some strangers. Since his father remains permitted to eat the figs, the others also remain permitted. This is true even if he says, “Person A and person B are prohibited, and my father is permitted.” However, if he says, “Had I known that my father was with you, I would have said that you’re all prohibited except for my father,” then they’re all prohibited except for the father. This is because he revealed through his words that his intention wasn’t to permit part of his vow, but rather to make the same vow but with a condition regarding his father.

Hilchos Nedarim 8:7

The same is true if someone says, “Wine is to me like an offering because it’s bad for the digestion” and he later learns that aged wine is good for digestion. If he says, “Had I known, I wouldn’t have made a vow” or “I would prohibited new wine and permitted aged wine,” both types of wine remain permitted to him. However, if he says, “Had I known, I would have prohibited all wine to me except for aged wine,” then he is only permitted to drink aged wine. The same is true in all comparable cases.