Numbers 18:12-18

12I give you all the freshest olive oil and all the finest new wine and grain that the Israelites give to the LORD as their firstfruits. 13The firstfruits of everything in their land that they bring to the LORD will belong to you. Every ceremonially clean person in your household may eat them.

14Every devoted thing in Israel belongs to you. 15The firstborn of every womb, whether man or beast, that is offered to the LORD belongs to you. But you must surely redeem every firstborn son and every firstborn male of unclean animals. 16You are to pay the redemption price for a month-old male according to your valuation: five shekels of silver,1 according to the sanctuary shekel, which is twenty gerahs.2

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.