Leviticus 25:32-33

³²And the cities of the Levites, the houses of the cities of their inheritance, may be always redeemed by the Levites (or, be a perpetual redemption for the Levites).

³³And (so of him) who purchaseth of the Levites, the purchased house in the city of their possession shall go out at the Jubilee; for the houses of the cities of the Levites are their inheritance among the sons of Israel.