Numbers 8:12-14

New Revised Standard Version, Anglicised Catholic Edition

¹² The Levites shall lay their hands on the heads of the bulls, and he shall offer one for a sin-offering and the other for a burnt-offering to the Lord, to make atonement for the Levites. ¹³ Then you shall have the Levites stand before Aaron and his sons, and you shall present them as an elevation-offering to the Lord.

¹⁴ Thus you shall separate the Levites from among the other Israelites, and the Levites shall be mine.