A SHALI'ACH WHO SOLD THE WRONG AMOUNT
Objection: Since the Seifa discusses selling too cheaply, surely the Reisha teaches something else!
(Seifa): If her Kesuvah was 400, and she sold 100, and another 100, and the last sale was worth 101 and she sold it for 100, the last sale is void and the other sales stand.
Answer: Both the Reisha and Seifa discuss selling too cheaply;
The Seifa teaches that the sale is void only because she sold the orphans' property (i.e. the last Dinar, which she was not entitled to) too cheaply, We infer that when she sells her property (what she is entitled to) too cheaply, the sale stands.
Question: The Reisha teaches this!
(Mishnah): If a widow's Kesuvah was 200 Dinarim and she sold property of the orphans which was worth 100 for 200, or property worth 200 for 100, in either case she has received her full Kesuvah.
Answer: One might have thought that the sale stands (when she sold too cheaply) only when the sale completes payment of her Kesuvah;
However, when she is still entitled to collect more, we would decree that the sale is void, lest people say that the sale stands even when she sold more than she was entitled to!
The Seifa teaches that there is no such decree.
Version #2: If a man told a Shali'ach 'Sell for me (land fitting to sow) 15 Sa'im' and the Shali'ach sold 30, clearly he fulfilled his mission and added to it. (The sale of 15 stands.)
Question: If a man told a Shali'ach 'Sell for me 30' and the Shali'ach sold 15, what is the law?
Can the Shali'ach say 'I did even better than you requested! Had I sold the full amount, and you did not need the money, you would not be able to retract. (But now, you will retain half the land!)'
Or, can the owner say 'I do not want (to sell to two people because this will cause) that there will be many documents saying that I sold land'?
Answer #1 (R. Chanina from Sura - Mishnah): Reuven gave to Shimon a gold Dinar and asked him to buy a cloak. Shimon spent half the money for a cloak, and half for a Talis. If the money was found to be Hekdesh, both transgressed Me'ilah.
If buying less than one was told is considered fulfilling the mission, we understand why Reuven transgressed Me'ilah. (Shimon fulfilled his mission, and he himself added to it the purchase of a Talis.)
Question: If it is considered changing the mission, why did Reuven transgress?
Rejection: Shimon spent half the Dinar and bought a cloak worth a full Dinar.
Question: If so, why did Shimon transgress Me'ilah?
Answer: He bought a Talis with the rest of the money.
Question (Seifa - R. Yehudah): Even here Reuven did not transgress Me'ilah, for he can say 'I wanted a big cloak, and you brought me a small, bad one.'
If it is worth a Dinar, why does he call it bad?
Answer: It is 'bad' in price!
Reuven says 'had you spent the full Dinar on a cloak, you would have gotten one worth (more than) two Dinarim.'
Support (Beraisa): R. Yehudah admits that both transgressed Me'ilah if he was sent to buy pulse (a legume, and spent half the money on pulse and half on something else), for pulse is sold at the same rate whether one buys a lot or a little.
Question: What is the case?
If it is where pulse is sold by estimation, one receives a better rate when buying in quantity!
Answer (Rav Papa): Rather, it is in a place where one receives a fixed measure for each Perutah.
Answer #2 (to Question (f) - Mishnah): If her Kesuvah was 400, and she sold 100, and another 100, and the last sale was worth 101 and she sold it for 100 - the last sale is void, the other sales stand. (This shows that a smaller sale is valid.)
Rejection: The case is like Rav Shisha brei d'Rav Idi said (below), the orphans inherited small plots of land that are not normally sold to one buyer.
SELLING TO TOO MANY BUYERS
Obviously, if he said 'sell to one buyer, not to two', a sale to two is invalid.
Question: If he said only 'sell to one person', if he sold to two what is the law?
Answer #1 (Rav Huna): Here also, he meant 'sell to one buyer, not to two.'
Answer #2 (Rav Chisda and Rabah bar Rav Huna): He meant 'sell to one, or even to two, or even to 100.'
Question (Rav Chisda and Rabah bar Rav Huna to Rav Nachman): How do you hold in such a case?
Answer (Rav Nachman): He meant 'sell to one, or even to two, or even to 100.'
Question (Rav Chisda and Rabah bar Rav Huna): Is the sale valid even if the Shali'ach erred?
Answer (Rav Nachman): No.
Question (Rav Chisda and Rabah bar Rav Huna): But it was taught (Rashi; Tosfos - you yourself said), the sale of land is not subject to the law of overcharging!
Answer (Rav Nachman): That is when the owner sells. If a Shali'ach sells, the owner says 'I authorized you to help me, not to harm me!'
The following shows that we distinguish between the owner and a Shali'ach.
(Mishnah): If Reuven told a Shali'ach to take Terumah, the Shali'ach should take like Reuven wants. If he does not know, he should take like an average person, one part in 50. If he took one in 40 or one in 60, the separation is valid.
(Beraisa): Even if he (the owner himself) took one in 20 (by mistake), the separation is valid.
Support (for Rav Nachman - Mishnah): If her Kesuvah was 400, and she sold 100, and another 100, and the last sale was worth 101 and she sold it for 100, the last sale is void and the others stand. (Even though the orphans did not say anything, we must ensure that they are not harmed. If selling to too many buyers invalidates a sale, her sale should be void!)
Rejection (Rav Shisha brei d'Rav Idi): This is no proof. The case is, the orphans inherited small plots of land that are not normally sold to one buyer.
IF BEIS DIN ERRED
(Mishnah): If Beis Din assessed property (to sell to feed the orphans or widow) for a sixth more or less than the actual value, the sale is void;
R. Shimon ben Gamliel says, the sale stands. If it were void, Beis Din would be weak!
If a letter of announcement (that the property is for sale) was made, even if property was sold for double or half the value, the sale stands.