Numbers 18:23; Numbers 18:24

23 "Only the Levites shall perform 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 sons of Israel they shall have no inheritance.

24 "For the tithe of the sons of Israel, which they offer as an offering to the LORD , I have given to the Levites for an inheritance; therefore I have said concerning them, 'They shall have no inheritance among the sons of Israel.' "