One of the laws of Yovel, the Jubilee year, is that property that was sold is automatically returned to its original owner (Vayikra 25:28). However, this does not apply to all property, as houses that are within walled cities (“walled” meaning that it was walled when the land was conquered by Yehoshua and “city” meaning more than just two courtyards containing two houses each, see Toras Kohanim) remain with the buyer even after Yovel (25:30). A friend asked me why houses within walled cities are different. After all, if “the land shall not be sold permanently, for the land is Mine (G-d’s), for you are strangers and sojourners with Me” (25:23), why can some property be sold “permanently” (25:30)?
There are actually three categories of property, each with its own set of laws regarding its sale. Agricultural land is sold “according to the number of years of crops” (25:15), with the land automatically reverting to its original owner at Yovel. Until then, the seller and his relatives have the right to “redeem” the land, i.e. buy it back at a prorated price based on how many years are left until Yovel (25:25-27). However, this “right” only starts after the land has been used by the buyer for two years (see Rashi on 15:15). Houses that are not within walled cities also automatically return to their original owners at Yovel, but the right to “redeem” it starts right away, not just after two years (see Rashi on 25:31). The third category is houses within a walled city, with the seller able to buy it back at anytime within the first year. After that, though, the new owner must agree to sell it back if he wants to regain ownership. If we are to understand why these houses can be sold permanently while no other property can be, we should try to understand all the differences between the categories, not just this one difference.
According to the Chinuch (Mitzvah #330), the land returning to its original owner teaches us that everything belongs to G-d, and will ultimately end up in the possession of the person He wants it to be in. Knowing this will discourage attempts to steal land from others (or even thinking about doing so), as the land will eventually be returned to its original owner anyway. He compares it to a king who occasionally uses eminent domain to take possession of property from local governors just to show who really owns it. If this lesson is only a “local” one (regarding land that can’t be sold permanently), it won’t discourage forcibly taking houses in walled cities (since they can change ownership permanently), and it can’t be suggested that there’s no need to teach this lesson elsewhere too. Indeed, the Chinuch (Mitzvah #340) says that not being able to “redeem” a house in a walled city after the first year is a sort of fine levied against the seller for not cherishing the Holy Land enough to make sure to buy the house back within the year. (In Mitzvah #341 he adds that not letting him buy it back after a year is meant as an incentive to encourage him to buy it back quickly.) If the “starting point” is that property can be sold permanently, with only some property not being able to be sold permanently in order to demonstrate Who really owns the land (i.e. G-d), we wouldn’t need a separate reason why houses in walled cities can be sold permanently.
No explanation is provided by the Chinuch for why houses that are not in walled cities can be “redeemed” right away (like houses within walled cities) yet can’t be sold permanently and can be redeemed even after the first year (like fields, which can be redeemed after the second year).
Midrash Tanchuma (Behar 1) compares our being in exile to land in the Holy Land being sold; just as G-d “sold” us into exile but eventually redeems us, so too when we sell land it must eventually be redeemed/returned to its original owner. No explanation is given as to how these two things are similar (is it merely because both are “special” to G-d?), nor are the other types of property discussed. It could be suggested that G-d not completely giving up on us despite our not fulfilling His expectations is being compared to the land not producing as much as we expected it to. If the landowner could get the land to produce more than he can sell the land for (taking into account the amount of work he must do and/or the expense of hiring others to do it for him), he wouldn’t have sold it in the first place. (For example, why sell the land for $1,000 for 10 years if he could get it to produce crops worth more than $1,000 over and above his costs? Put another way, if it’s worthwhile for the buyer to pay that much to use the land, why isn’t it worthwhile for the owner to keep it?) Nevertheless, G-d wants us not to give up on ever being able to get the land to provide more than selling it provides (whether that means improving our ability to farm the land or our ability to hire workers who can do it for us), so only allows for leases, not permanent sales. This is analogous to our not doing what we are supposed to do yet G-d not giving up on us, waiting for us to turn things around and be worthy of redemption.
If this is what the comparison is based on, we can understand why houses, which provide shelter rather than income, don’t fit within the comparison. Because it’s not a matter of generating income, instead of giving the original owner the opportunity of redeeming his land any time after two years (which gives the buyer some use of the land) if he now thinks he can work the land more efficiently, and having it revert back to him at Yovel, residential houses can be sold permanently, while giving the seller a year to reconsider. Houses that are not within walled cities are often only used to provide shelter for those working in the nearby fields, so must be able to be redeemed with those fields, as well as being returned to its original owner with the fields at Yovel. By the same token, since some houses are purely residential (even if not within a walled city), the seller is given the opportunity to change his mind even within the first year of the sale (as is the case for the purely residential houses within a walled city). [Once the seller can “redeem” it within the first year (like houses within a walled city) and can redeem it after two years (like fields), he is allowed to “redeem” it within the second year as well.]
Ramban explicitly differentiates between residential property and property used to provide income (see also Bechor Shor and Chizkuni). Income-producing property must be returned at Yovel because everyone needs a source of income. Even though everyone also needs a place to live, once they move to a different location, Ramban says it is difficult to have to move back, so residential property can be sold permanently. Houses in un-walled cities were meant for those who worked the fields (not just, or necessarily, the owners), so have the same status as the fields themselves. (These commentators do not address why such houses can be redeemed within the first two years, but the implication is that since sometimes even houses in un-walled cities are only used as a residence, without any connection to crop-producing fields or taking care of livestock, they can be redeemed immediately, just as houses in walled cities can be.)
Having an ancestral home has many advantages, and having property revert to its original owner every Yovel maintains these advantages. However, there are some distinct disadvantages as well. For example, where would converts live? How would they support themselves in a primarily agricultural society? The same is true of members of a different Tribe that moved from their ancestral home to a different part of the Promised Land. [There could be several very good reasons to do so. For example, when the king of the Northern Kingdom set up golden calves at alternative worship sites for the thrice yearly pilgrimages and prevented his subjects from going to the Temple in Jerusalem, there were individuals who permanently moved to the Southern Kingdom. The same issue would arise if a husband moved in with his wife’s family, although he could “sell” his property after every Yovel.] Granted, there would always be a need for workers, and other skills could be harnessed to generate income. But if no property could be permanently sold, there would be no way for a non-resident to ever be a home owner, even if he could support his family. As Chizkuni points out (albeit not regarding converts or out-of-Tribe dwellers), if one couldn’t permanently own their home, there would be little new construction in a walled city (where, apparently, most people lived), including not expanding existing structures, if the person doing the construction didn’t permanently own the home.