Deuteronomy 14:21-22

Ye shall not eat of any thing that dieth of itself: thou shalt give it unto the stranger that is in thy gates, that he may eat it; or thou mayest sell it unto an alien: for thou art an holy people unto the LORD thy God. Thou shalt not seethe a kid in his mother's milk. Thou shalt truly tithe all the increase of thy seed, that the field bringeth forth year by year.