Numbers 18:17-19

17But you must not redeem the firstborn of an ox, a sheep, or a goat; they are holy. You are to splatter their blood on the altar and burn their fat as a food offering, a pleasing aroma to the LORD. 18And their meat belongs to you, just as the breast and right thigh of the wave offering belong to you.

19All the holy offerings that the Israelites present to the LORD I give to you and to your sons and daughters as a permanent statute. It is a permanent covenant of salt1 before the LORD for you and your offspring.”