Numbers 18:20-23
English Standard Version
21"To the Levites I have given every tithe in Israel for an inheritance, in return for their service that they do, their service in the tent of meeting,
22so that the people of Israel do not come near the tent of meeting, lest they bear sin and die.
23But the Levites shall do the service of the tent of meeting, and they shall bear their iniquity. It shall be a perpetual statute throughout your generations, and among the people of Israel they shall have no inheritance.