1) A FORCED REDEMPTION
QUESTION: The Gemara quotes a Beraisa which teaches that when one is Makdish his Sedeh Achuzah during the time that the laws of the Yovel year do not apply, Beis Din forces the owner of the field to redeem it. However, the Mishnah in Bechoros (13a) teaches that mid'Oraisa the redemption (of objects sanctified to Hekdesh) by the original owner is merely "l'Mitzvah," preferable, but not obligatory. (This is similar to the Mishnah's teaching that it is preferable to perform Yibum rather than Chalitzah, but it is not obligatory.) Why, then, does the Gemara here rule that Beis Din forces the owner to redeem his field? (TOSFOS DH Mai)
(a) RABEINU GERSHOM implies that the case of redeeming a sanctified field is different. Beis Din forces the owner to redeem the field because Hekdesh will benefit from the extra fifth that the owner must pay upon redemption.
(b) TOSFOS answers that Beis Din wants someone to redeem the field lest people inadvertently use the field for personal benefit and transgress the prohibition of Me'ilah (using a sanctified object for personal benefit). Therefore, Beis Din forces the original owner to redeem the field.
(c) The RAMBAM (Hilchos Erchin 5:1, according to the RADBAZ) explains that Beis Din forces the owner to redeem the field because of the profit to Hekdesh in the principle value of the field (and not just the additional fifth that the owner must add). If the owner does not redeem the field, there is a concern that perhaps no one at all will redeem the field. (Accordingly, when the laws of the Yovel year are observed, Beis Din does not force him to redeem the field because the Kohanim will acquire the field upon Yovel if he does not redeem it.)
2) LET THE OWNER SAY, "THIS MAN SHOULD BE IN MY PLACE!"
OPINIONS: The Mishnah teaches that when the original owner of a sanctified field bids 20 Sela'im to redeem the field, and a rival bidder offers the same, the original owner must redeem it because he is required to add a fifth to his bid and thus Hekdesh benefits. If the rival bidder offers 21 Sela'im, then the original owner is required to redeem it for 26 -- the principle bid of the second bidder plus the fifth of his own bid (20) that he must add because he is the original owner. If the rival bidder offers 25 for the field, then the original owner is required to redeem it for 30.
The Gemara asks that in the latter case, the original owner should be entitled to say, "This man should be in my place," and the rival bidder should have to redeem the field.
There are two fundamentally different approaches to understanding the Gemara's question.
(a) RASHI explains that since the second person is bidding what the original owner (who bid 20, and would have to pay 25 with the added fifth) would have had to pay, there is no reason to make the original owner redeem it any more than the second bidder. In the earlier cases, when the second person bid 21, 22, 23, or 24, Hekdesh is entitled to force the original owner to redeem it for that value plus the additional 5 Sela'im, because the second person's bid establishes the principle value of the field to be worth more than the value that the owner's bid ascribed to it, and thus Hekdesh would lose if the owner would pay only 25.
This explanation is difficult to understand for two reasons. First, it is always preferable for the original owner to redeem the property even if another bid matches his own. Second, since he bid first, how can he exempt himself with this claim? When two bidders offer the same price for the field, the one who bid first should be the one who is required to pay.
(b) The RAMBAM (Hilchos Erchin 8:5-7) understands that the Gemara is not suggesting that the original owner can exempt himself completely with this claim, but rather that he should be able to exempt himself from paying any additional amount above the bid of the second person. He should be able to protest, "If you (Hekdesh) want the extra money, then take it from this person in my place," and he should not have to pay more than the 20 Sela'im that he bid plus the extra fifth (for a total of 25). According to this understanding, the question of the Gemara does not refer specifically to the case in which the second person bid 25, but it refers to the cases in which the second person bid 21, 22, 23, and 24 as well.
The Gemara answers that the Mishnah is discussing a case in which the original owner now accepts upon himself to add an additional Perutah above the additional principle value that the second person bid. For example, if the second person bid 25, the original owner now says, "I will redeem it for 25 and a Perutah (instead of the 20 that I originally bid)." The Mishnah teaches that in such a case he is required to pay 30 and a Perutah. He does not have to add a fifth to the amount that he added to his first bid (5 Sela'im and a Perutah), because he raised his bid only in order to match the bid of the rival bidder, and not because he assessed the field to be worth this new amount.
The Rambam disagrees with the other Rishonim in two points. First, if the original owner bid 20 and someone else bid 25, the original owner has the first obligation to redeem the field. Second, if the original owner added a Perutah above the higher bid of the second person and said that he would redeem the field for 25 and a Perutah, he does not add a fifth to what he added above the second person's bid.