QUESTION: The Mishnah discusses a case in which a man dies after his wife gives birth, for the first time, to twin boys, before giving five Sela'im to a Kohen to redeem one of them. Rebbi Meir maintains that if the sons themselves gave five Sela'im before they divided their father's estate, the Pidyon ha'Ben takes effect. If, however, they divided the estate first, they are exempt from giving any money for Pidyon ha'Ben.
The Gemara asks when exactly did the father die. The Mishnah cannot be discussing a case in which the father died more than thirty days after the boys were born, because Rebbi Meir would not have said in such a case that after the estate has been divided the sons are exempt from Pidyon ha'Ben. Once thirty days have passed, a financial obligation takes effect on the father to pay the Kohen, and his properties become collateralized to the debt. It must be, therefore, that the father died before thirty days passed.
The Gemara then asks that if the father died before thirty days passed, then why is there a difference between a case in which the sons paid the Kohen before dividing the estate and a case in which they first divided the estate? In a case in which they first divided the estate, the reason why they are exempt is that when the Kohen claims the money from each son, each son will defer the Kohen to his brother, claiming that his brother is the Bechor and not he. However, they also should be able to make that claim before the estate is divided! Why, then, does the obligation of Pidyon ha'Ben take effect?
Rebbi Yirmeyah answers that the Mishnah is teaching that when a lien takes effect on one's jointly-owned property, he cannot defer the creditor to his partner. Hence, in a case of two partners with the same name (Yosef ben Shimon) in the same town who own a field together, when one of the partners owes money, the creditor may collect his debt from the field. Even though each Yosef ben Shimon will say to the creditor, "It is not I who owes you the money, but rather my partner who shares my name," the creditor may take the field owned by them as partners because he can say to the first Yosef ben Shimon, "If it is you who owes me money, then I am collecting it from your half of the field, and if it is the other Yosef ben Shimon who owes me money, then I am collecting it from his half of the field."
RASHI (DH Shnei) explains that, similarly, when the Kohen collects from the estate that has not yet been divided, he may say to each son, "If you are the real Bechor, then I am collecting the money from your portion, and if your brother is the real Bechor, then I am collecting it from his portion. It is the responsibility of the two of you to divide what is left of the estate after I have taken my five Sela'im."
According to Rebbi Yirmeyah, why may the creditor of Yosef ben Shimon collect from the jointly-owned field? The deed that he holds against Yosef ben Shimon is worthless and proves nothing, because there is no evidence in the Shtar itself to prove which Yosef ben Shimon owes the money. (Conversely, a deed of sale in the possession of one Yosef ben Shimon would not effect a transaction, because there is no proof in the deed itself as to who made the transaction.) The witnesses do not have to see the transfer of funds for every transaction regarded in a loan document, because the Shtar functions to obligate the borrower to pay money to the lender even before he has actually borrowed it. Therefore, the Shtar against Yosef ben Shimon represents neither the creation of an obligation nor the transfer of money. If the Shtar is not valid, then how can Rebbi Yirmeyah say that the two Yosefs become obligated to the lender?
ANSWER: The KETZOS HA'CHOSHEN (49:9 DH v'Nir'eh) answers that it must be that Rebbi Yirmeyah maintains that even though there is no proof from the Shtar itself that a particular Yosef ben Shimon owes money, the Shtar does prove that there is a lien on the property owned jointly by both Yosefs. The Shtar proves that the property itself is obligated to repay the debt. Therefore, even though there is no proof that any individual Yosef ben Shimon is obligated, there is proof that the field owes money to the lender, so to speak, because it is known for certain that he loaned money to one of the Yosefs and this field certainly is available to pay back the loans taken by either Yosef ben Shimon. (D. BLOOM)
QUESTION: The Gemara suggests that the Tana'im in the Mishnah agree that the obligation of Pidyon ha'Ben, which is a "Milveh ha'Kesuvah ba'Torah" (a monetary obligation arising from a Torah law), is not considered like a debt for which a contract was written (and thus there is no lien on the father's property for that debt).
Whether a "Milveh ha'Kesuvah ba'Torah" has the status of a verbal loan or a contractual loan is the subject of a Machlokes (Erchin 6b and other places), and as the Gemara later (48b) concludes with regard to the Machlokes Tana'im in the Mishnah here. According to the opinion that a "Milveh ha'Kesuvah ba'Torah" is considered a monetary obligation written in a contract, why is not every loan, even ones with no written contract, also not considered a contractual loan? The Torah states that one must fulfill his word and pay back his loan when he takes a loan verbally (Devarim 24:11), and thus even a verbal loan is a "Milveh ha'Kesuvah ba'Torah"! Why, then, do all verbal loans not effect a lien on the borrower's property, according to this opinion?
ANSWER: TOSFOS here (DH Milveh) explains that the fact that a monetary obligation appears in the Torah does not automatically give it the status of a "Milveh ha'Kesuvah ba'Torah." Only an obligation that would not have been known logically had it not been written in the Torah is considered a "Milveh ha'Kesuvah ba'Torah." The obligation to return a loan is logical and self-evident, and therefore it is not considered a "Milveh ha'Kesuvah ba'Torah." (According to Tosfos, the term "Milveh ha'Kesuvah ba'Torah" refers to a monetary obligation that the Torah teaches, and not to a monetary obligation that the Torah merely mentions.)
It is interesting to note that Tosfos refers to Nezikin (compensation owed for damages) as a "Milveh ha'Kesuvah ba'Torah." This implies that without the law of Nezikin in Torah, the obligation to pay for damages would not have been self-evident (for more on this, see Insights to Bava Kama 2:3). (Tosfos' assertion that Nezikin is considered a "Milveh ha'Kesuvah ba'Torah" is apparently based on the Gemara in Erchin 6b. See, however, Tosfos in Bava Kama (8a, DH Kulan), who seems to be in doubt about this.)


OPINIONS: The Gemara concludes that everyone agrees that a person cannot be obligated to pay two and a half Sela'im (one for each Safek Bechor) for Pidyon ha'Ben. He must pay five Sela'im in full, or he has no obligation to pay at all.
Does this concept apply to other Mitzvos as well? The Gemara in Yoma (74a) teaches that in cases of Isurim d'Oraisa, "half of a Shi'ur" (Chatzi Shi'ur) is also prohibited (mid'Oraisa, according to Rebbi Yochanan there). When a person partially transgresses an Isur such as by eating less than the minimum Shi'ur of a prohibited food, he transgresses a Torah prohibition even though he is not subject to punishment in the hands of Beis Din. Does the same concept apply to one who partially fulfills a Mitzvah? For example, if one eats less than the required Shi'ur of Matzah on Pesach night, has he fulfilled half of the Mitzvah, or has he fulfilled nothing, as though he ate no Matzah at all?
(a) The MISHNEH L'MELECH (Hilchos Chametz u'Matzah 1:7) and KESAV SOFER (OC 96) prove from the Gemara's ruling here with regard to Pidyon ha'Ben that a person is not rewarded at all for a partial fulfillment of a Mitzvas Aseh, and that he is not considered to have fulfilled any degree of the Mitzvah. The Kesav Sofer rules, therefore, that if one has in his possession less than a k'Zayis of Matzah on the first night of Pesach, he is not obligated to eat it since he will not fulfill any Mitzvah by doing so.
The MAHARIT ALGAZI (8:81:8) adds that although a partial performance of a Mitzvah is the same as not doing the Mitzvah at all, when a person gives two and a half Sela'im for Pidyon ha'Ben as the first installment of a payment that he intends to pay in full, he is considered to have performed a partial Mitzvah.
(b) The ONEG YOM TOV (OC 100) explains that one is rewarded for a partial fulfillment of a Mitzvah just as he is punished for a partial violation of an Isur. One who eats less than a k'Zayis of Matzah is rewarded for performing a partial Mitzvah. Pidyon ha'Ben is different, because the Torah defines the act of Pidyon as giving five Sela'im. Giving anything less is not a Mitzvah; it is not an act of Pidyon at all. (RAV MOSHE SHAPIRO shlit'a explained the logic of this ruling as follows. The Torah commands the Bechor's father to "remove his debt" to the Kohen by giving five Sela'im, and not merely to "transfer funds" to the Kohen. For this reason, when he gives the Kohen anything less than five Sela'im, he has not even begun the performance of the Mitzvah, since the debt has not been removed.)