Numbers 8:10-20

10 When you present the Levites before the LORD, the people of Israel shall lay their hands upon the Levites,
11 and Aaron shall offer the Levites before the LORD as a wave offering from the people of Israel, that it may be theirs to do the service of the LORD.
12 Then the Levites shall lay their hands upon the heads of the bulls; and you shall offer the one for a sin offering and the other for a burnt offering to the LORD, to make atonement for the Levites.
13 And you shall cause the Levites to attend Aaron and his sons, and shall offer them as a wave offering to the LORD.
14 "Thus you shall separate the Levites from among the people of Israel, and the Levites shall be mine.
15 And after that the Levites shall go in to do service at the tent of meeting, when you have cleansed them and offered them as a wave offering.
16 For they are wholly given to me from among the people of Israel; instead of all that open the womb, the first-born of all the people of Israel, I have taken them for myself.
17 For all the first-born among the people of Israel are mine, both of man and of beast; on the day that I slew all the first-born in the land of Egypt I consecrated them for myself,
18 and I have taken the Levites instead of all the first-born among the people of Israel.
19 And I have given the Levites as a gift to Aaron and his sons from among the people of Israel, to do the service for the people of Israel at the tent of meeting, and to make atonement for the people of Israel, that there may be no plague among the people of Israel in case the people of Israel should come near the sanctuary."
20 Thus did Moses and Aaron and all the congregation of the people of Israel to the Levites; according to all that the LORD commanded Moses concerning the Levites, the people of Israel did to them.
Revised Standard Version of the Bible, copyright 1952 [2nd edition, 1971] by the Division of Christian Education of the National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved.