Numbers 8:8-12

8Have them take a young bull with its grain offering of the finest flour mixed with olive oil; then you are to take a second young bull for a sin offering.

9Bring the Levites to the front of the tent of meeting and assemble the whole Israelite community.

10You are to bring the Levites before the Lord, and the Israelites are to lay their hands on them.

11Aaron is to present the Levites before the Lord as a wave offering from the Israelites, so that they may be ready to do the work of the Lord.

12“Then the Levites are to lay their hands on the heads of the bulls, using one for a sin offering to the Lord and the other for a burnt offering, to make atonement for the Levites.