Numbers 8:21-23

New Revised Standard Version Catholic Edition

²¹ The Levites purified themselves from sin and washed their clothes; then Aaron presented them as an elevation offering before the Lord, and Aaron made atonement for them to cleanse them. ²² Thereafter the Levites went in to do their service in the tent of meeting in attendance on Aaron and his sons. As the Lord had commanded Moses concerning the Levites, so they did with them.

²³ The Lord spoke to Moses, saying: