Numbers 18:23-24

23Only the Levites shall perform the service of the Tent of Meeting (tabernacle), and they shall bear their iniquity; it shall be a statute forever throughout your generations, that the Levites shall have no inheritance [of land] among the children of Israel.

24But the tithe of the Israelites, which they present as an offering to the Lord, I have given to the Levites as an inheritance; therefore I have said to them, ‘They shall have no inheritance among the children of Israel.’ ”