Deuteronomy 23:19-25

“Do not charge interest on the loans you make to a fellow Israelite, whether you loan money, or food, or anything else. You may charge interest to foreigners, but you may not charge interest to Israelites, so that the LORD your God may bless you in everything you do in the land you are about to enter and occupy. “When you make a vow to the LORD your God, be prompt in fulfilling whatever you promised him. For the LORD your God demands that you promptly fulfill all your vows, or you will be guilty of sin. However, it is not a sin to refrain from making a vow. But once you have voluntarily made a vow, be careful to fulfill your promise to the LORD your God. “When you enter your neighbor’s vineyard, you may eat your fill of grapes, but you must not carry any away in a basket. And when you enter your neighbor’s field of grain, you may pluck the heads of grain with your hand, but you must not harvest it with a sickle.