Numbers 8:19-21

New King James Version

¹⁹ And ^(A)I have given the Levites as a gift to Aaron and his sons from among the children of Israel, to do the work for the children of Israel in the tabernacle of meeting, and to make atonement for the children of Israel, ^(B)that there be no plague among the children of Israel when the children of Israel come near the sanctuary.”

²⁰ Thus Moses and Aaron and all the congregation of the children of Israel did to the Levites; according to all that the Lord commanded Moses concerning the Levites, so the children of Israel did to them. ^21 (C)And the Levites purified themselves and washed their clothes; then Aaron presented them like a wave offering before the Lord, and Aaron made atonement for them to cleanse them.