1) THE INFERENCE FROM "MA'OS SETUMIN"
QUESTION: The Beraisa discusses the case of a person who is obligated to bring a Korban Chatas (to atone for a sin he committed) and accepts upon himself to bring a Korban Olah as well. If he separates money and says, "This money is for my obligation [to bring a Korban]," he may not use the entire sum for a Chatas or an Olah alone. (Rather, he must use the money to buy both Korbanos, according to Tosfos.) The Beraisa continues and says that "if he dies and leaves Ma'os Setumin (money which he set aside but did not designate for one of the two Korbanos), the money must be thrown into the Yam ha'Melach."
TOSFOS (24b, DH Hayu Lo and DH Yiplu) explains that if a person who is obligated to bring a Chatas and an Olah sets aside money for the purpose of purchasing either a Chatas, Olah, or both, when he dies the money is not thrown into the Yam ha'Melach but rather it is used to purchase a Korban Nedavah (an Olah). (This applies whether he must bring a Chatas because he is a Nazir or for another reason.) The only situation in which it is necessary for the Halachah l'Moshe mi'Sinai to teach that the money is used to bring a Korban Nedavah is when the person specifically designated the money to be used to bring both a Chatas and an Olah. Since he needed to use some of the money for a Chatas, although the money normally would be thrown into the Yam ha'Melach when he dies (or becomes unable to bring the Korban for some other reason), the Halachah l'Moshe mi'Sinai teaches that it is to be used to bring a Korban Nedavah.
Tosfos explains that when the Gemara earlier (24b) quotes the Mishnah which states that money set aside, but not specifically designated, should be used for a Nedavah, the Gemara infers that the Mishnah refers not only to money not designated for any specific Korban but even to money designated for a Chatas as well as for other Korbanos. That is why the Gemara must invoke the Halachah l'Moshe mi'Sinai as the reason for why the money is to be used for a Nedavah. The same applies to the Beraisa (beginning of 26a) which discusses Kinim. How does the Gemara know that the money was designated to be used for a Chatas as well as an Olah? The answer is that the beginning of the Mishnah and Beraisa discuss money which was set aside for Korbanos but not designated for a specific type, and the Mishnah and Beraisa continue, "If he dies and he has unspecified money...." Why do the Mishnah and Beraisa need to repeat that "he has unspecified money" if the Reisha also discusses such money? It must be that the Seifa is adding that if the person has money that was specified for use for specific Korbanos but how much of the money to spend on the Chatas was not specified (he specified only that "some" of it will be used for a Chatas), the money still is used for a Nedavah.
According to Tosfos, why does the Beraisa -- which discusses the case of a person who is obligated to bring a Chatas and accepts upon himself to bring an Olah -- state that if the person dies and has unspecified money set aside, it must be thrown into the Yam ha'Melach? Even in the case of the Reisha of the Beraisa, the person designated some of the money for a Chatas, and thus the words in the Seifa "he had Ma'os Setumin" add nothing to the case of the Reisha. The Beraisa should omit those words and say only, "If he dies, the money must be thrown into the Yam ha'Melach."
ANSWER: The section of Tosfos (24b) in which Tosfos makes the inference from the words, "He had Ma'os Setumin," is actually a Hagahah and is not the words of Tosfos himself. It is possible that the Hagahah did not explain the Sugya here like Tosfos but like RABEINU AZRIEL (as cited in the SHITAH MEKUBETZES).
Rabeinu Azriel explains that the "Ma'os Setumin" of the Reisha of the Beraisa refers to money designated for the purchase of a Chatas or an Olah, or both (like the "Ma'os Setumin" in the Reisha of the other Beraisa and Mishnah). The Seifa, however, refers to a case in which the person designated the money for both the Chatas and the Olah. In the case of the Reisha, the money indeed will not be thrown into the Yam ha'Melach (but will be used for a Nedavah), because it is possible that all the money was intended to be used for an Olah. It is not included in the Halachah l'Moshe mi'Sinai of "Chata'os Mesos" since the Halachah l'Moshe mi'Sinai might refer only to money definitely designated for a Chatas.
2) WHAT TO DO WITH MONEY SET ASIDE FOR KORBANOS BUT NOT SPECIFICALLY DESIGNATED
QUESTION: The Beraisa discusses the case of a person who is obligated to bring a Korban Chatas (to atone for a sin he committed) and accepts upon himself to bring a Korban Olah as well. If he separates money and says, "This money is for my obligation [to bring a Korban]," he may not use the entire sum for a Chatas or an Olah alone. (See previous Insight.)
The Mishnah cited earlier (24b) states that a Nazir who separates money for his Korbanos may use all of the money to bring any one of his Korbanos. The Gemara earlier (on this Daf) cites another Beraisa which states that a person who separates money for a pair of birds (a Chatas and an Olah) may use all of the money to buy either a Chatas or an Olah. Why, then, in the case of the Beraisa here may he not use all of the money to buy a Chatas or an Olah?
ANSWERS:
(a) TOSFOS explains that the expression "l'Chovasi" ("for my obligation [to bring a Korban]") implies that the person wants to bring from this money everything he is obligated to bring. (It is comparable to one who separates money and says "these are for the Korbanos of my Nezirus" and not just "these are for my Nezirus." See Tosfos, end of 24b.)
(b) Tosfos suggests further that the reason why this case is different from the other cases is that in this case the two Korbanos for which he separated the money are unrelated to each other. Consequently, when he designates money for his obligation (for the Olah or Chatas), the money becomes consecrated towards both obligations. In the case of the Nazir, however, he set aside money for the general obligation of "Korbenos Nazir," which includes all three of the Korbanos of a Nazir. If he spends money on any one of the Korbanos, it has been spent on "Korbenos Nazir."
According to Tosfos, in this case he must spend some portion of the money on the Chatas and some portion of the money on the Olah.
The ROSH, who expresses a logic similar to that of Tosfos, rules that it does not help for the person to spend a portion of the money for the Chatas and a portion for the Olah. Rather, since he dedicates the money "for a Chatas or an Olah," the money becomes designated for one or both of the Korbanos. He has no way of knowing for which it has become designated. Therefore, the only way for him to use the money is to add additional money and sanctify it for whatever Korban the first money was not designated for, and then buy the Chatas and Olah with the combined sum of money.
(c) The RAMBAM (Hilchos Pesulei ha'Mukdashin 5:13) has a different Girsa in the Beraisa. According to his Girsa, the Beraisa states that the person may bring either a Chatas or an Olah with the money, and thus this Beraisa is consistent with the other Mishnah and Beraisa.

26b----------------------------------------26b

3) ARE BIRDS CONSIDERED "MA'OS SETUMIN"
QUESTION: Rav Huna in the name of Rav says that when a Nazir separates unfit animals for the Korbanos of his Nezirus (which must be left to become blemished and then redeemed, and the money is used to buy animals fit for Korbanos), if the Nazir dies the value of the animals he separated must be thrown into the Yam ha'Melach and is not used for Nedavah. The value of the animals does not have the status of "Ma'os Setumin" (money set aside to be used for Korbanos but which was not designated for any specific Korbanos). Rather, the value of the animals is considered "Ma'os Mefurashin" (specified for particular Korbanos).
Rav Shimi bar Ashi asks that if the Halachah of Ma'os Setumin applies only to money and not to animals, it also should apply only to money and not to birds. Rav Chisda, however, states that when a woman buys a pair of birds in order to bring one as a Chatas and one as an Olah (for her Korban Yoledes), she may designate which one is the Chatas and which is the Olah only at the time she buys the birds, or the Kohen may designate the birds at the time he offers them on the Mizbe'ach. If birds are not considered "Ma'os Setumin," the Kohen should not be able to designate the birds at the time he offers them because the birds should be considered designated already ("Mefurashin").
Rav Shimi bar Ashi's comparison of the Kohen's ability to designate birds for a Chatas and an Olah to the law of Rav Huna -- that the value of the animals is considered designated for a Chatas -- is difficult to understand. Even if money is designated for a Chatas with regard to the requirement that it be thrown into the Yam ha'Melach, nevertheless it still is possible for the owner of the Korban to designate which part of the money will be used for a Chatas. For example, if he says that "this money is for my Chatas, Olah, and Shelamim," the money must be thrown into Yam ha'Melach if he dies, but if he does not die he may decide which part of the money will be used to buy the Chatas and other Korbanos.
ANSWERS:
(a) TOSFOS explains that the reason why the value of the animals must be thrown into the Yam ha'Melach is that the owner cannot use the value to buy his Korban right away (since he must wait for the animal to become blemished). There is a concern that he might have designated some of the value of those animals to be used for his Chatas, and thus that value is considered "Mefurashin." If, however, he designates money -- and not animals -- to use for his Korbanos, there is no concern that he set aside part of the money for the Chatas, because had he wanted to set aside money for the Chatas he simply would have bought a Chatas with it. The concern exists only when he set aside animals for his Korbanos, in which case he cannot simply buy a Chatas with them. He must wait until they get a blemish and are redeemed, at which time there is a concern that he set aside some of the money for his Chatas.
Accordingly, Tosfos explains the question of Rav Shimi as follows. After the woman buys the pair of birds she cannot choose which one will be the Chatas. Rather, the Kohen -- when he offers them -- designates one as the Chatas and the other as the Olah. Since the owner cannot choose which one will be the Chatas and the birds must wait in their undesignated state until they are offered, there is a concern that as time passes the owner might mentally designate one as the Chatas and the other as the Olah. Although such a designation does not take effect (with regard to the Halachah of "Chatas Mesah") -- since the bird obtains the status of a Chatas only at the time the Kohen designates it, nevertheless the owner's mental designation limits the Kohen to designating as the Chatas the same one that the owner designated in his mind. (See following Insight.)
(b) The ROSH adds that according to Rebbi Yochanan, who states that a Halachah l'Moshe mi'Sinai teaches that Ma'os Setumin are used to buy a Korban Nedavah, the Halachah l'Moshe mi'Sinai does not apply to animals designated to be offered as Korbenos Nazir. This is logical: A person cannot set aside something to remain indefinitely "Setumin," unspecified money. A person can set aside money as Ma'os Setumin only when that money could be used immediately for the purchase of the respective Korbanos, and thereby becoming specified, "Mefurashin." When the money (or value) cannot be used immediately for the purchase of Korbanos, it cannot remain Setumin, and instead it is considered as though he specified that this money will be used for the Chatas, Olah, and Shelamim. Since the value of an animal designated for the Korbanos of Nezirus cannot be used to buy Korbanos until the animal becomes blemished, it cannot be considered Setumin. Rav Shimi bar Ashi is asking that if this rule is correct, it should not be possible for birds to remain Setumin and for the owner not to be able to designate them for their respective Korbanos. They should become Mefurashin immediately for a Chatas and an Olah.
The Rosh maintains that when money becomes specified, Mefurashin, for particular Korbanos, this does not mean that the owner may choose later which part of the money to use for which Korban. Rather, part of the money becomes designated for each Korban and it is impossible to know which part is designated for which Korban (see previous Insight). Therefore, if the pair of birds becomes designated for the respective Korbanos, the Kohen cannot choose later which will be the Chatas and which will be the Olah.
(c) The RAM (cited by Tosfos, 27a) and the ROSH in his second explanation write that the Gemara's question is straightforward. Rav Huna in the name of Rav says that if a person designates the value of animals towards his Korbanos, there is a concern that he might have chosen part of the value to be used as the Chatas (as mentioned in (a) above). Rav Shimi bar Ashi questions this from Rav Chisda's rule that one may designate a Korban only at the time he buys the Korban or at the time the Kohen offers it, but not at any other time. The same applies to money set aside for a Korban; it may be designated for a certain type of Korban only when one buys the Korban. It should be impossible for him to designate the value for a Chatas before he actually uses the money to buy a Chatas.
According to this explanation, Rav Chisda's statement relates not only to Kinim but to all Korbanos. Although the Hagahah in Tosfos (and the ME'IRI) reject this explanation, the TOSFOS YESHANIM and RITVA (Yoma 41a) point out that this indeed seems to be the way the Gemara in Yoma (41a) understands Rav Chisda's words, since it applies his teaching to the two Se'irim of Yom Kippur and not only to Kinim.
(d) The HAGAHAH in TOSFOS offers a simple (albeit forced) explanation. He suggests that Rav Chisda's wording implies that not only are the birds considered undesignated with regard to which will be offered as a Chatas, but they are not considered designated even with regard to leaving the birds to die (in a case where the owner has died).