Leviticus 25:32-34

Notwithstanding the cities of the Levites, and the houses of the cities of their possession, may the Levites redeem at any time.

Notwithstanding the cities ... 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 (Numbers 35:4). 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 (Jeremiah 31:7).