Numbers 8:20-22

Revised Standard Version

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. ²¹ And the Levites purified themselves from sin, and washed their clothes; and Aaron offered them as a wave offering before the Lord, and Aaron made atonement for them to cleanse them. ²² And after that the Levites went in to do their service in the tent of meeting in attendance upon Aaron and his sons; as the Lord had commanded Moses concerning the Levites, so they did to them.