Numbers 8:11

7 This is what you must do to cleanse them: Sprinkle them with the water of purification. Have them shave their whole bodies and wash their clothes, and so purify themselves.

8 Then have them take a young bull with its grain offering of fine flour mixed with oil, and you are to take a second young bull for a sin offering.

9 Bring the Levites before the Tent of Meeting and assemble the whole congregation of Israel.

10 You are to present the Levites before the LORD and have the Israelites lay their hands upon them.

11 Aaron is to present the Levites before the LORD as a wave offering from the sons of Israel, so that they may perform the service of the LORD.

12 And the Levites are to lay their hands on the heads of the bulls, and offer to the LORD one as a sin offering and the other as a burnt offering, to make atonement for the Levites.

13 You are to have the Levites stand before Aaron and his sons and then present them before the LORD as a wave offering.

14 In this way you shall separate the Levites from the rest of the Israelites, and the Levites will belong to Me.

15 After you have cleansed them and presented them as a wave offering, they may come to serve at the Tent of Meeting.

Read all of Numbers 8