John Wesley on Numbers 18:20

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 incumbrances; 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.