Deuteronomy 23:23-25

You must do whatever you say you will do, because you chose to make the promise to the LORD your God. If you go into your neighbor’s vineyard, you may eat as many grapes as you wish, but do not put any grapes into your basket. If you go into your neighbor’s grainfield, you may pick grain with your hands, but you must not cut down your neighbor’s grain with your sickle.