Numbers 18:20

Here is a further account of the provision that was made both for the Levites and for the priests, out of the country. I. They must have no inheritance in the land; only cities to dwell in were afterwards allowed them, but no ground to occupy: Thou shalt not have any part among them, Num 18:20. It is repeated again Num 18:23, and again Num 18:24, Among the children of Israel they shall have no inheritance, either by purchase or descent. God would have them comfortably provided for, but would not have their families over-rich, lest they should think themselves above that work which their wages supposed and obliged them constantly to attend upon. As Israel was a peculiar people, and not to be numbered among the nations, so Levi was a peculiar tribe, and not to be settled as the rest of the tribes, but in all respects distinguished from them. A good reason is given why they must have no inheritance in the land, for, says God, I am thy part, and thy inheritance. Note, Those that have God for their inheritance and their portion for ever ought to look with a holy contempt and indifference upon the inheritances of this world, and not covet their portion in it. "The Lord is my portion, therefore will I hope in him, and not depend upon any thing I have on this earth," Lam 3:24.

— Matthew Henry's Concise Commentary (public domain)