Commentaire sur Le Lévitique 25:31

ובתי החצרים BUT THE HOUSES OF THE VILLAGES — Understand this as the Targum does: פצחין i. e. “houses of open cities” such as have no rampart. The term חצר occurs many times in this sense in the Book of Joshua, e.g., (Joshua 13:29) “the cities and the unwalled places thereof (וחצריהם)”; so also (Genesis 25:16) "by their unwalled places (בחצריהם) and by their strongholds” (see Rashi on that verse).

Without cost. I.e., without compensation. Because regarding an ancestral field it is taught in a Beraisa, “If [the buyer] used it for a year and the jubileeJubilee year arrived, he has to add another year for [the buyer] after the jubileeJubilee year [because generally one cannot redeem a field before two years have passed]. Therefore one needs the extra words “and it is released by the jubileeJubilee,” to teach that it goes out without cost, without adding [an extra year]. [See] Erchin 29b.

ובתי החצרים, “but the houses of the villages;” seeing that such houses are frequently transformed into fields, they are considered as an integral part of the legislation as it applies to fields, which means that they revert to the original owner in the Jubilee year. (Compare Ibn Ezra in his abbreviated commentary).