Numbers 8:11-14

Aaron is to present the Levites before the LORD as a presentation offering from the Israelites, so that they may perform the LORD’s work.  Next the Levites are to lay their hands on the heads of the bulls. Sacrifice one as a sin offering and the other as a burnt offering to the LORD, to make atonement for the Levites.  “You are to have the Levites stand before Aaron and his sons, and you are to present them before the LORD as a presentation offering. In this way you are to separate the Levites from the rest of the Israelites so that the Levites will belong to me.