GEMARA

24a (Mishnah): If a Nezirah designated money Stam (without specifying how much is for each Korban) for her Korbanos and her husband annulled her Nezirus, it goes to Nedavah.

(R. Yochanan): This law is a tradition from Sinai regarding a Nazir.

25b - Question: It applies also to other matters!

(Beraisa #1): (A Ken is a pair of birds. One will be offered for a Chatas, and the other for an Olah. Oleh v'Yored is a Korban for which rich people bring animals, and an Oni brings birds.) If one who must bring a Ken (for Oleh v'Yored) designated money for it (and then became rich), he may use all the money for Chatas Behemah (an animal) if he wants, or all for Olas Behemah;

If he died, leaving Stam money (he did not specify how much is for each Korban), it goes to Nedavah.

Answer: The law applies to Nazir and those who must bring Kinim, for they are similar (they must bring a Chatas and an Olah). R. Yochanan said "regarding a Nazir" to exclude the following:

(Beraisa #2): If Reuven was obligated to bring a Chatas and he vowed to bring an Olah, and he separated money and said 'this is for my obligation', he may not use all the money for an animal for the Chatas or Olah ('my obligation' connotes all that he must bring);

If he died, leaving Stam money (for the Korbanos), we cast it into the Dead Sea.

RISHONIM

Rambam (Hilchos Pesulei ha'Mukdashim 5:11): If anyone obligated to bring a Ken separated coins for it, he may use all the money for the Chatas or all for the Olah if he wants. Even if he said 'these coins are for my Chatas, and these are for the Olah', he can mix the money and buy both or just one from it. A Ken becomes Mefurash only when the owner buys it or when the Kohen offers it.

Rambam (12): Therefore, if he separated money for Kinim Stam and died, all the money goes to Nedavah, for all could have been used for Olah.

Question (Ri Korkus): The Gemara concluded that Stam coins go to Nedavah due to Rav Chisda's teaching. The Rambam teaches that coins are unlike birds. Even if he said at the time of designation (when Perush helps for birds), he can use the money for either. However, why does he discuss Stam money in Halachah 12? Money is always Stam!

Answer #1 (Ri Korkus): Perhaps one can change money from its designation, but l'Chatchilah one should not.

Answer #2 (Ri Korkus): Stam is whenever he did not say that they are for his Chovah (obligation), even if he specified Chatas or Olah, but he cannot offer them for Nedavah if he said that they are for his Chovah.

Rambam (13): If Reuven was obligated to bring a Chatas and he vowed to bring an Olah, and he separated money and said 'this is for my obligation', he may use all the money for an animal for the Chatas or Olah if he wants. If he died, leaving money, we cast it into the Dead Sea.

Ra'avad: This is in the Gemara and Tosefta (Me'ilah 1:5). The Tosefta says that he cannot use all the money for the Chatas or Olah. This is more proper than the Gemara, for once he vowed, also the Olah is a Chovah, and it is mixed with the Chatas. If all could be brought for Olah, why must we cast the money to the Dead Sea?!

Kesef Mishneh: The Ra'avad rejects the Rambam's text, for if all the money could be used for Olah, the money would go to Nedavah, just like Stam money for Kinim. Perhaps the correct text of the Rambam allows using all for Chatas, but not for Olah, because one would not abandon a prior Chiyuv and use all the money for a later Chiyuv, especially since the former is a Chatas (which atones).

Ri Korkus: Our text of the Rambam says only that he may use all for Chatas. His text of the Gemara permitted using it for Chatas, but not for Olah. 'My Chiyuv' does not connote what he accepted upon himself. Had he intended for the Olah, or for both, he would have specified. Surely he may not choose which to bring, so the Rambam did not need to explicitly forbid Olah. It is like any Chatas: if the owner died, the money goes to the Dead Sea. Some texts say that he can bring Chatas or Olah, i.e. he can clarify what he intended. If he died, the money goes to the Dead Sea, for perhaps he would have explained that he intended for Chatas.

Kesef Mishneh: Also the text of the Tosefta is difficult. Why can't he use it all for Olah? In Halachah 11 we permit this even if Demei Chatas and Demei Olah were mixed! Perhaps the Ra'avad said that the Tosefta is more proper, i.e. also it is difficult. The Gemara is more difficult, for it contradicts itself.

Ri Korkus: Our text of the Beraisa says that the money cannot be used for either. Rashi explains that we are concerned lest it is for the other Korban. There is no solution because the Chiyuvim came separately.

Tosfos (26a DH u'Le'afukei): He cannot bring Chatas or Olah. The only solution is to bring two animals, and say 'all Kedushas Chatas is on this animal (and all Kedushas Olah is on the other).'

Question: Why is this different than Stam money for a Ken or Nezirus, which can be used all for any Korban?

Answer (Tosfos): Perhaps 'my Chiyuv' connotes all that he is obligated, therefore he cannot use all for either Korban. 'For my Nezirus' or 'for my Tzara'as' can mean even for one of the Korbanos. Alternatively, he can use all the money for any of the Korbanos only when a common source obligates bringing them.

Lechem Mishneh: This answers the Kesef Mishneh's difficulty with the Tosefta

Tosfos (DH Mes): R. Yochanan does not argue with Beraisa #2. He merely says that the law (of Beraisa #1, of Stam money) does not apply in the case of Beraisa #2.

Perush ha'Rosh (DH v'R. Tam): R. Tam says that the Tana of Beraisa #2 argues with Beraisa #1.