Numbers 18:16-18

King James Version

¹⁶ And those that are to be redeemed from a month old shalt thou redeem, according to thine estimation, for the money of five shekels, after the shekel of the sanctuary, which is twenty gerahs.

¹⁷ But the firstling of a cow, or the firstling of a sheep, or the firstling of a goat, thou shalt not redeem; they are holy: thou shalt sprinkle their blood upon the altar, and shalt burn their fat for an offering made by fire, for a sweet savour unto the Lord.

¹⁸ And the flesh of them shall be thine, as the wave breast and as the right shoulder are thine.