Yesterday, we noted the question raised by the Ramban, in his commentary to Parashat Behar (25:14), regarding the prohibition of ona’a, which forbids charging or paying an unfair price for merchandise. The Mishna (Bava Metzia 56a) establishes that this law applies specifically to metaltelin (moveable property), and not to karka’ot (land), yet, the Torah establishes this prohibition in reference to the transaction of lands and how their value is affected by yovel. The Torah introduces the command of ona’a in instructing buyers and sellers to set the price of land fairly, in consideration of the fact that land sales are only temporary, as lands in Eretz Yisrael return to their original owner on the jubilee year. It thus seems difficult to understand why the prohibition of ona’a would specifically not apply to karka’ot. As we saw, the Ramban proposed that the prohibition in fact does apply to land exchanges, and it is only in regard to some of the details (such as the revocation of the sale in certain instances) that the Mishna limits ona’a to metaltelin.
In concluding his discussion, however, the Ramban proposes a different theory. He alludes to the Gemara’s comment in Masekhet Kiddushin (42b) that one form of ona’a indeed applies even to karka’ot – namely, imprecise measurements. Lands sales are excluded only from the prohibition against overvaluing property beyond its market value. Given the permanence of real estate, a piece of land can never be truly overvalued, and thus it can be assumed that the buyer accepts the price despite its significantly exceeding market value. If, however, a party was given actual misinformation, such as about the size of the property, then the law of ona’a indeed applies, since nobody would accept a bad price determined based on misinformation. Therefore, the Ramban writes, the Torah introduces ona’a in the context of its discussion of yovel and how it affects the pricing of land, because unfair pricing of this type is indeed included in the ona’a prohibition. If the price is set according to a mistaken calculation of the years remaining until yovel, then this is akin to misinformation regarding the property’s size, and thus the resulting unfair price falls under the prohibition of ona’a. (This explanation is also given by Seforno.)
Interestingly, in presenting this theory, the Ramban writes that the Torah here forbids misleading the other party with regard to the number of years remaining until yovel, and he then adds, “Rather, they must both know and inform each other of the number.” The Ramban seems to understand the law of ona’a as not only forbidding one party from misleading the other, or taking advantage of the other’s lack of knowledge of the relevant information, but also requiring them to present this information to one another. It seems that in the Ramban’s view, it does not suffice to avoid misleading a buyer or seller, and they must be very clear and open with one another about the relevant “facts and figures” that affect the property’s value, to ensure that both are aware of the amount it is worth. (This observation is made by Rav Yitzchak Rokowsky in his Imrei Yitzchak, Parshat Behar.)