Numbers 18:6

18:6 I myself have chosen your brothers the Levites from among the Israelites. They are given to you as a gift from the Lord, to perform the duties of the tent of meeting.

Numbers 18:23

18:23 But the Levites must perform the service of the tent of meeting, and they must bear their iniquity. It will be a perpetual ordinance throughout your generations that among the Israelites the Levites have no inheritance.