1)WHEN IS A SMALL MISTAKE PARDONED?
(a)(Gemara) Question: If Reuven told Shimon 'I sell to you a Beis Kor' (and did not mention measure by a rope, nor 'less or more'), what is the law?
(b)Answer #1 (Mishnah): If he said 'I sell to you a Beis Kor, measured by a rope', if it is any amount less, Shimon deducts from the price; if it is any amount more, Shimon returns the extra.
1.Inference: Had he not said this, there would be no compensation.
(c)Objection (Seifa): If he said 'be it less or more', even if there is a Rova too little or too much per Se'ah, there is no compensation.
1.Had he not said this, there would be compensation!
(d)Conclusion: The inferences contradict one another. We cannot answer our question from the Mishnah, because we do not know which inference is correct.
(e)Answer #2 (Beraisa): If he said 'I sell to you a Beis Kor', 'I sell to you approximately a Beis Kor', 'I sell to you a Beis Kor, be it less or more', even if there is a Rova too little or too much per Se'ah, there is no compensation.
1.Inference: If he did not specify, it is as if he said 'be it less or more'!
(f)Rejection: The Beraisa does not give three separate cases, rather it all explains one case;
1.It means, when is selling a Beis Kor like selling approximately a Beis Kor? It is if he said 'I sell to you a Beis Kor, be it less or more.
(g)Objection (Rav Ashi): If so, it should not say 'I sell to you' three times!
1.Rather, the Beraisa settles our question. If he did not specify, it is as if he said 'be it less or more.'
2)WHAT IS RETURNED
(a)(Mishnah): He returns money to him...
(b)Question: Is it really true that we give the seller his choice, and not the buyer?!
1.Contradiction (Beraisa): If the amount of land was seven and a half Kavim per Kor too little or too much, the sale stands. If it was more than this, we force the seller to sell the extra (the buyer can say 'I do not want to have to guard myself from you') and the buyer to buy it (the seller has little use for a small field).
(c)Answer: Really, we do not force the seller to sell the extra land;
1.The Beraisa teaches that if the value of the land declined, the buyer can say 'if you insist that I buy the extra land, I will pay only today's lower price.'
(d)Question (Beraisa): When the seller makes the buyer buy the extra land, it is according to the price at the time of the original sale.
(e)Answer: That is when the price increased.
3)WHEN THE SELLER CANNOT DEMAND MONEY
(a)(Mishnah): If the extra is Beis nine Kavim (he returns land).
(b)(Rav Huna): This applies even if there were nine extra Kavim in a sale of a giant valley.
(c)(Rav Nachman): It applies only if there were seven and a half extra Kavim for each Kor (if not, the extra is pardoned);
(d)When (there is this much extra per Kor, and) the extra is nine Kavim, since it is a proper field, Reuven cannot force Shimon to buy it.
(e)Question (Rava, against Rav Nachman - Mishnah): If the extra is Beis nine Kavim in a field...
1.Assumption: (Even if) the field is two Kor, so there are only four and a half extra Kavim for each Kor, he must return it!
(f)Answer (Rav Nachman): No, he sold only one Kor.
(g)Question (Rava - Mishnah): Or half a Kav in a garden...
1.The garden is Se'atayim, so there is only an extra Rova Kav for each Se'ah. Normally one pardons this, but since it is the size of a proper garden, he must return it!
(h)Answer (Rav Nachman): No, he sold only one Se'ah.
(i)Question (Mishnah): According to R. Akiva, a Beis Rova.
1.The case is, the garden is one Se'ah.
(j)Answer: No, he sold only a half Se'ah.
(k)Question (Rav Ashi): If he sold a field, and there was more than an extra Rova for each Se'ah, and the total was at least a half Se'ah but less than nine Kavim, and the land became fit for a garden, or vice-versa (he sold a garden, now it is only fit for a field), what is the law?
(l)This question is not resolved.
(m)(Beraisa): If Reuven kept a field bordering the sold field, Shimon can insist that Reuven take back the extra land (it is fitting for him), even if it is less than nine Kavim.
(n)Questions (Rav Ashi): If any of the following separate between Reuven's field and the field he sold: a pit, an irrigation channel, a Reshus ha'Rabim, or a row of date trees, what is the law?
(o)These questions are not resolved.
(p)(Mishnah): He does not return just the Rova for each Se'ah. He returns all the extra land.
(q)Question: Just the contrary! The Chidush is that he returns the extra Rova'im!
(r)Answer (Ravin bar Rav Nachman): Indeed, the text should say 'he does not just return the extra above the Reva'im. He returns the extra Reva'im as well.