Leviticus 25:30-33

30And if it be not redeemed within the space of a full year, then the house that is in the walled city shall be made sure in perpetuity to him that bought it, throughout his generations: it shall not go out in the jubilee. 31But the houses of the villages which have no wall round about them shall be reckoned with the fields of the country: they may be redeemed, and they shall go out in the jubilee. 32Nevertheless the cities of the Levites, the houses of the cities of their possession, may the Levites redeem at any time. 33And if one of the Levites redeem, then the house that was sold, and the city of his possession, shall go out in the jubilee; for the houses of the cities of the Levites are their possession among the children of Israel.