Thou shalt have no inheritance in their land In the land of the children of Israel. You shall not have a distinct portion of land, as the other tribes shall. The reason of this law was partly because God would have them wholly devoted to his service, and therefore free from worldly encumbrances, partly because God had abundantly provided for them otherwise, by tithes, and first-fruits, and oblations, and partly that, by this means, being dispersed among the several tribes, they might have the better opportunity for teaching and watching over the people. I am thy part I have appointed thee a liberal maintenance out of my oblations.
Related Commentaries of Numbers 18:20
Numbers 18:20
20 And the LORD spake unto Aaron, Thou shalt have no inheritance in their land, neither shalt thou have any part among them: I am thy part and thine inheritance among the children of Israel.