[What are] nedarim with conditions unavoidably unfulfilled? His friend vowed in order that he eat with him, but he took ill, or his son took ill, or he was held back by a river —- these are nedarim with conditions unavoidably unfulfilled.

One may make a neder for murderers, robbers, or illegal tax collectors that it is terumah, even though it is not terumah; that they belong to the royal house, even though they do not belong to the royal house.  Beis Shammai say: One may make any neder, but not an oath; Beis Hillel, however, say: Even an oath. Beis Shammai say: He should not volunteer to make a neder; Beis Hillel, however, say: He may even volunteer. Beis Shammai say: Only what he is forced to vow; Beis Hillel, however, say: Even what he is not forced to vow. How [is this]? They told him: “Say: `Konam, my wife benefiting from me,' ” and he said: “Konam my wife and my children benefiting from me” —- Beis Shammai say: His wife is permitted, but his children are forbidden. Beis Hillel, however, say: Both are permitted.