2,660. An Oath to Eat Something Prohibited

Hilchos Shevuos 5:12

If someone takes an oath to eat neveila, treifa or something else prohibited by the Torah, he is liable to the penalty of lashes for making a vain oath regardless of whether or not he actually ate the thing in question.

Hilchos Shevuos 5:13

If someone takes an oath to eat a certain loaf and not to eat that loaf, the second oath is a vain oath because he is obligated to eat it. He is liable to lashes for the second oath regardless of whether or not he eats the loaf. If he doesn’t eat it, he is also liable for violating an oath of expression.