Numbers 8:11
11 and Aaron shall offer the Levites before the Lord as a wave offering from the people of Israel, that they may do the service of the Lord.
Numbers 8:15
15 And after that the Levites shall go in to serve at the tent of meeting, when you have cleansed them and offered them as a swave offering.
Numbers 8:24
24 “This applies to the Levites: bfrom twenty-five years old and upward they1 shall come to do duty in the service of the tent of meeting.
Numbers 8:26
26 They minister1 to their brothers in the tent of meeting cby keeping guard, but they shall do no service. Thus shall you do to the Levites in assigning their duties.”