Jamieson, Fausset and Brown on Leviticus 25:32-34

32-34. Notwithstanding the cities of the Levites, &c.--The Levites, having no possessions but their towns and their houses, the law conferred on them the same privileges that were granted to the lands of the other Israelites. A certain portion of the lands surrounding the Levitical cities was appropriated to them for the pasturage of their cattle and flocks (Nu 35:4, 5). This was a permanent endowment for the support of the ministry and could not be alienated for any time. The Levites, however, were at liberty to make exchanges among themselves; and a priest might sell his house, garden, and right of pasture to another priest, but not to an Israelite of another tribe (Jr 41:7-9).