2,647. An Oath to Get Out of an Invitation

Hilchos Shevuos 4:8

Let’s say that a person’s friend is badgering him to eat at his home, specifically to drink wine, milk, and honey. If he replies with an oath not to drink wine, milk, and honey, he renders himself separately liable for eating each one. In order to minimize liability, one should take an oath “not to drink anything,” or “what you said,” referring to his friend’s words. By specifying each item, he expresses an intention to take an oath regarding each one separately. In such a case, the drinks don’t combine to form the minimum volume and one is only liable for imbibing the minimum volume of each beverage by itself. Since each beverage would require its own sin offering, they’re like fat and blood, which don’t combine to form the minimum volume of an olive as was discussed in Maachalos Assuros 4:16.

Hilchos Shevuos 4:9

If a person takes an oath to not eat a certain loaf, and he eats an olive’s volume of it, he is liable; if his oath was that he wouldn’t finish it,* he isn’t liable until he eats the whole thing. If he took an oath not to eat the loaf and not to finish it, he is only liable once for eating from it.

*There’s a nuance in the Hebrew from which we infer that to “eat it” means to finish it, but it doesn’t really translate.