Numbers 18:16-18

Revised Standard Version

¹⁶ And their redemption price (at a month old you shall redeem them) you shall fix at five shekels in silver, according to 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, you shall not redeem; they are holy. You shall sprinkle their blood upon the altar, and shall burn their fat as an offering by fire, a pleasing odor to the Lord; ¹⁸ but their flesh shall be yours, as the breast that is waved and as the right thigh are yours.