2,761. Eating Today, Traveling Tomorrow

Hilchos Nedarim 4:13

Let’s say that someone made a vow not to benefit from the people of a certain city and he sought to permit his vow from the rabbi of that city, or he made a vow not to benefit from the Jewish people and he sought to permit his vow from a Torah authority, who is invariably Jewish. In cases such as this, the vow is effectively permitted.

Hilchos Nedarim 4:14

Let’s say that someone declares produce to be prohibited today if he travels to a certain place tomorrow. In such a case, he may not eat the produce today out of concern that he might go to that place tomorrow. If he violated and ate from the produce on day 1, and he then went to that place on day 2, he is liable to the penalty of lashes; if he didn’t go to that place, he isn’t liable to lashes.