פָּחוֹת מִשְּׁתוּת - נִקְנֶה מִקָּח? מקורות

§ Rav Naḥman says: With regard to brothers who divided property received as an inheritance, they are considered like they are purchasers from each other, and the halakhot of fraud are like those for regular transactions: If there was an error of less than one-sixth in the distribution, the transaction is acquired, i.e., valid. If it was more than one-sixth, the transaction is void. If the error was precisely one-sixth, it is acquired, and the one who received more than his fair share must return the amount of the fraud.Rava says: That which we said, that with regard to less than one-sixth the transaction is valid and the item is acquired, we said only in a case where the brother receiving a smaller share did not appoint an agent to deal with the distribution on his behalf. But if the brother receiving a smaller share appointed an agent, this halakha does not apply, as the one who appointed the agent can say: I sent you to act for my benefit and not to my detriment. The agent’s right to act in this capacity did not extend to a case where it was to the detriment of the one who appointed him. Rava continues: And that which we said, that if the brothers erred by more than one-sixth the transaction is void, we said only when the brother receiving a smaller share did not say: Let us divide the estate by an appraisal of the court. But if he said: Let us divide it by an appraisal of the court, the transaction is valid, as we learned in a mishna (Ketubot 99b): This is the halakha with regard to the appraisal of an article’s value in order to sell it, as done by the judges: In a case where they decreased the price by one-sixth of its market value or added one-sixth to its market value, their sale is void. Rabban Shimon ben Gamliel says: Their sale is valid.Rava continues: And that which we said, that if the brothers erred by one-sixth the one receiving a larger share acquired it and he must return the amount of the fraud, we said only with regard to movable property. But with regard to land, the halakha is that there is no fraud with regard to land. And with regard to land, we said that the halakha of fraud does not apply only when they divided it according to the value of the land. But if they divided it by measure and erred in the measurement, we do not say that there is no fraud. This is in accordance with the statement of Rabba, as Rabba said: Any matter that is according to measure, or according to weight, or according to number, if it turned out to be in error, even if the error was less than the amount that constitutes fraud, it is also returned.

MISHNA: The halakha with regard to the assessment of the judges of the value of a piece of property in order to sell it is as follows: Where they decreased the price by one-sixth of its market value or added one-sixth to its market value, their sale is void.Rabban Shimon ben Gamliel says: Their sale is valid. If it were so that the sale is void, then what advantage is there to the power of the court over an ordinary person? However, if they made a document of inspection, i.e., an announcement that people should come to inspect the field and bid on the property, then even if they sold property worth one hundred dinars for two hundred dinars, or sold property worth two hundred dinars for one hundred dinars, their sale is valid, as the transaction was agreed upon and done publicly. GEMARA:A dilemma was raised before the Sages: An agent who mistakenly sold land for less than its value is like whom? Is he comparable to a judge, whose sale is effective if he did not err by more than one-sixth of the market price, or is he comparable to a widow, whose sale is void if she sold for anything less than the market price? Rava said that Rav Naḥman said: The halakha with regard to the agent is like the halakha pertaining to the judges. Rav Shmuel bar Bisna said that Rav Naḥman said: The halakha with regard to the agent is like the halakha with regard to a widow.