1) THE COMPARISON BETWEEN "HODA'AS BA'AL DIN" AND "HIS'CHAYEVUS"
QUESTION: The Gemara (101b) records a dispute between Rebbi Yochanan and Reish Lakish about the law in the case of a person who writes in a Shtar that he owes money to another person. The Gemara there explains that the question involves whether or not one's act of writing an admission of debt in a Shtar is akin to admitting to a debt in the presence of witnesses, in which case he may not say later that he was joking. Does such an admission written in a Shtar constitute a "Hoda'as Ba'al Din" which obligates him like a hundred witnesses or not?
The Gemara suggests that the Machlokes between Rebbi Yochanan and Reish Lakish is actually a Machlokes Tana'im. In the last Mishnah in Bava Basra (175b), Rebbi Yishmael and Ben Nanas disagree about the law in the case of a person who saw his friend in trouble when he was unable to repay a loan. In order to help his friend he told the creditor, "I will pay back [his debt]." Rebbi Yishmael rules that he is obligated to pay the debt, and Ben Nanas rules that he is not obligated to pay the debt. Rebbi Yochanan, who says that a written admission of debt is considered "Hoda'as Ba'al Din," follows the view of Rebbi Yishmael. Reish Lakish follows the view of Ben Nanas.
The Gemara's comparison of the two cases is difficult to understand. It is clear that in Rebbi Yishmael's case there is no "Hoda'as Ba'al Din" at all. In that case, the benefactor's obligation to pay the debt is not due to any admission of debt, but rather it is due to his accepting upon himself the obligation of responsibility for the loan ("His'chayevus"). Why does the Gemara say that Rebbi Yochanan's opinion is consistent with that of Rebbi Yishmael, and Reish Lakish's with that of Ben Nanas?
(a) TOSFOS (DH k'Tenai) explains that Rebbi Yishmael and Ben Nanas actually argue about two points. Their first argument involves the status of a written admission. Their second argument involves the status of a written obligation. The Mishnah which records their dispute describes the case with the words, "An Arev (guarantor) who is signed below the signatures of the witnesses...." Clearly, the case in which they argue is one in which the guarantor signed his name at the end of the loan contract and no witnesses signed in attestation to his declaration. Accordingly, that case is one of a written admission, "Hoda'as Ba'al Din," the same case in which Rebbi Yochanan and Reish Lakish argue.
When Ben Nanas argues with Rebbi Yishmael and says that the guarantor who signed the contract after the signature of the witnesses is not obligated, Rebbi Yishmael responds, "Why?" ("Lamah?"). Rebbi Yishmael's response expresses two points. The first is that the guarantor should be obligated because of "Hoda'ah." The second is that even if the guarantor's acceptance of responsibility is not considered "Hoda'ah," he still should be obligated because of "His'chayevus" -- he obligated himself to pay. Ben Nanas answers by stating that certainly the guarantor is exempt in a case in which the guarantor obligates himself after the time of the loan (without signing the contract). That case, however, is unrelated to admission, "Hoda'ah." Clearly, Ben Nanas argues both when the guarantor's "Hoda'ah" is written in the contract, and when his verbal acceptance of responsibility is not a "Hoda'ah" but "His'chayevus."
(b) Tosfos cites another explanation in the name of RABEINU TAM. Rabeinu Tam understands that Rebbi Yochanan and Reish Lakish actually argue only in the case of "His'chayevus" and not in the case of "Hoda'ah." When the person writes in a Shtar that he owes money to someone, his intent is to obligate himself through the medium of the Shtar, and not necessarily to admit to a debt. This indeed is the subject of the dispute between Rebbi Yishmael and Ben Nanas.
How, though, can a person create a monetary obligation through the use of a Shtar? A Shtar is not a valid Kinyan for Metaltelin (Kidushin 26a)! Tosfos answers that the fact that he exerted the effort to write his obligation in a Shtar shows that he has conclusive intent to obligate himself. Such a display of intent is a valid way to create an obligation. (This is similar to the Gemara here which says, "These are the things which are acquired through speech alone," in reference to the conclusive intent (to become obligated) which the parties have due to the joy of the Shiduch.) Generally, a formal act of Kinyan is necessary to show one's conclusive intent to effect the transaction. When, however, the person's conclusive intent is evident in a different way, the Kinyan is valid without a formal act of Kinyan. (Mordechai Zvi Dicker)
2) WHEN IS THERE A SUSPICION OF "TZERORI"?
QUESTION: The Mishnah (101b) teaches that when a man married a woman and agreed to support her daughter (from a previous marriage) for five years and he died, the daughter may collect her Mezonos even from Nechasim Meshubadim. The Gemara explains that this applies when a Kinyan was made on the agreement to support her. In contrast, the man's own daughter may not collect her Mezonos from Nechasim Meshubadim even when there was a Kinyan.
The Gemara explains the difference as follows. Since a man is obligated to provide for his own daughter not only by his Kinyan but also by a Tenai Beis Din, we must suspect that before he died he left a bundle of money ("Tzerori") for her. Consequently, his daughter may not collect from Nechasim Meshubadim. In contrast, he is not obligated by a Tenai Beis Din to support his wife's daughter, and thus we do not suspect that he left "Tzerori" for her.
TOSFOS (DH Eimar) asks that if there is a suspicion of "Tzerori" when a Tenai Beis Din obligates a man to pay, why is a woman permitted to collect her Kesuvah from Nechasim Meshubadim? A Kesuvah certainly is a Tenai Beis Din!
(a) TOSFOS answers that a man is more concerned about the financial welfare of his daughter than of his wife, as the Gemara earlier (43a) states. Accordingly, the concern for "Tzerori" exists only for the support of one's daughter, but not for the payment of the Kesuvah of one's wife.
(b) Tosfos answers further than the Gemara does not mean that a Tenai Beis Din alone is cause for concern for "Tzerori." Rather, the Gemara means that since the man made a Kinyan in addition to the existing Tenai Beis Din, this is cause for concern for "Tzerori."
(c) The TOSFOS HA'ROSH in Gitin (51a) seems to differentiate between the obligation to pay the Kesuvah to one's wife and the obligation to pay Mezonos to one's daughter. The money of a woman's Kesuvah is a debt which the man owes. She has the status of a creditor. Therefore, a suspicion of "Tzerori" cannot stop her from collecting her Kesuvah from Nechasim Meshubadim, since the debt owed to her preceded the sale of the property to the buyers. In contrast, he does not owe anything to his daughter; his daughter is not a creditor per se. Rather, he merely is obligated to provide support for her because of a Tenai Beis Din. Accordingly, when there is a suspicion of "Tzerori" they may not collect from Nechasim Meshubadim, since they have no "debt" that preceded the buyer's purchase of his property. (Mordechai Zvi Dicker)