Numbers 8:13-15

Revised Standard Version

¹³ And you shall cause the Levites to attend Aaron and his sons, and shall offer them as a wave offering to the Lord.

¹⁴ “Thus you shall separate the Levites from among the people of Israel, and the Levites shall be mine. ¹⁵ And after that the Levites shall go in to do service at the tent of meeting, when you have cleansed them and offered them as a wave offering.