Numbers 8:8-12

8Then have them take a 1bull with 2its grain offering, fine flour mixed with oil; and you shall take a second 3bull as a sin offering.

9So 4you shall present the Levites in front of the tent of meeting. 5You shall also assemble the whole congregation of the sons of Israel,

10and present the Levites before the Lord; and the sons of Israel 6shall lay their hands on the Levites.

11Aaron then shall 7present the Levites before the Lord as a 8wave offering from the sons of Israel, so that they may 9qualify to perform the service of the Lord.

12Now 10the Levites shall lay their hands on the heads of the bulls; then you are to offer the one as a sin offering and the other as a burnt offering to the Lord, to make atonement for the Levites.