Leviticus 25:32-34

32As for the cities of the Levites, the houses in the cities which they possess, the Levites must have a perpetual right of redemption.

33Whatever someone among the Levites might redeem – the sale of a house which is his property in a city – must revert in the jubilee, because the houses of the cities of the Levites are their property in the midst of the Israelites.

34Moreover, the open field areas of their cities must not be sold, because that is their perpetual possession.