Numbers 18:14

11 And this is yours as well: the offering of their gifts, along with all the wave offerings of the Israelites. I have given this to you and your sons and daughters as a permanent statute. Every ceremonially clean person in your household may eat it.

12 I 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.

13 The 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.

14 Every devoted thing in Israel belongs to you.

15 The 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.

16 You are to pay the redemption price for a month-old male according to your valuation: five shekels of silver, according to the sanctuary shekel, which is twenty gerahs.

17 But you must not redeem the firstborn of an ox, a sheep, or a goat; they are holy. You are to sprinkle their blood on the altar and burn their fat as an offering made by fire, a pleasing aroma to the LORD.