The reason is from the great difference between such houses and lands. The reasons before alleged for lands do not hold in such houses; there was no danger of confusion in tribes or families by the alienation of houses. The seller also had a greater propriety in houses than in lands, as not coming to him by God's mere gift, but being commonly built by the owner's cost and diligence, and therefore had a fuller power to dispose of them. Besides, God would hereby encourage persons to buy and possess houses in such places, which frequency and fulness of inhabitants in cities was a great strength, honour, and advantage to the whole land.
Related Commentaries of Leviticus 25:30
Leviticus 25:30
30 And if it be not redeemed within the space of a full year, then the house that is in the walled city shall be established for ever to him that bought it throughout his generations: it shall not go out in the jubile.