Numbers 8:19-21

Amplified Bible, Classic Edition

¹⁹ And I have given the Levites as a gift to Aaron and to his sons from among the Israelites to do the service of the Israelites at the Tent of Meeting and to make atonement for them, that there may be no plague among the Israelites if they should come near the sanctuary.

²⁰ So Moses and Aaron and all the congregation of the Israelites did thus to the Levites; according to all that the Lord commanded Moses concerning [them], so did the Israelites to them.

²¹ The Levites cleansed and purified themselves and they washed their clothes; and Aaron offered them as a wave offering before the Lord and Aaron made atonement for them to cleanse them.