Numbers 8:21-23

Revised Standard Version

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.

²³ And the Lord said to Moses,