Mishnah three in the eighth chapter continues the topic of mixtures, and we have another case: "Asham she-nisarev b'shelamim" - a guilt-offering that became mixed up with a peace-offering.
The common denominator between the two offerings:
Both the asham and the shelamim have the same blood service: for both, the blood is dashed "two which are four", on two corners - the northeast and the southwest. From this perspective, there is no problem with the mixture.
The differences between them - the asham is stricter than the shelamim:
Place of slaughter: The asham must be slaughtered in the north of the Courtyard, whereas shelamim do not require the north.
Those who eat: The asham is eaten by kohanim only, while shelamim are eaten by anyone.
Place of eating: The asham is eaten only in the Courtyard.
Time for eating: The asham is eaten for one day, and shelamim for two days.
From this arises the question: why not treat both animals according to the strictures of the asham? The blood will be dashed identically, two which are four; the slaughtering will be done in the north; and the meat will be eaten according to the strictures of the asham - for kohanim, in the Courtyard and for one day. Even at the time of offering, making a mental stipulation will work: if this is an asham - it is an asham, and if this is a shelamim - it is a shelamim. Is this method valid? Regarding this, Rabbi Shimon and the Sages disagree: Rabbi Shimon permits it, and the Sages forbid it.
What could go wrong here? The blood is dashed properly, and the meat is eaten properly, and there is no flaw in the fact that the shelamim are eaten only by kohanim, only in the Courtyard, and only for one day. However, a separate rule governs this Mishnah, according to the view of the Sages and so is the halachah: one may not do an act that increases the likelihood that meat will remain uneaten in its proper time, and violate the prohibition of leaving meat over until it becomes nosar (leftover) and requires burning. Even though one could treat the doubtful shelamim with the strictures of the asham, by doing so one reduces the number of eaters (kohanim only) and shortens the time for eating (one day instead of two), and consequently the possibility that the meat will become nosar is increased. For this reason, we do not take this approach.
The language of the Mishnah:
"Asham she-nisarev b'shelamim" - the asham is kodshei kodashim, and the shelamim are kodashim kalim.
"Yir'u ad she-yista'avu" - this is the view of the Tanna Kamma, which is the approach of the Sages and so is the halachah: we leave both animals to graze until a blemish occurs in them, redeem both of them, he pays the value of the more expensive of the two and goes back and brings them, as was explained in the previous Mishnahs.
"Rabbi Shimon omer: Sheneihem yishachetu ba-tzafon" - he slaughters them according to the stricture of the asham, in the north of the Courtyard.
"V'yei'achelu k'chamur she-bahen" - he eats them in a way that satisfies the strictures of both, and every stricture involved in eating the asham applies to the shelamim as well.
"Amru lo: Ein mevi'in kodashim l'veis ha-pesul" - we do not perform an act that increases the possibility that the meat will not be eaten in its time, and will come to the state of nosar that requires burning.
A practical implication in our days:
This rule affects our lives as well, and this is not a common occurrence. One does not bring a todah offering on Erev Pesach, because the time is short and the ten chametz loaves of the todah cannot be eaten on Pesach. Similarly, one does not bring a todah or other offerings that are eaten on Erev Yom Kippur, since there is no possibility to eat them on the following night, as Yom Kippur has already begun - and therefore one does not bring it to begin with. For this reason, it is customary to skip "Mizmor L'sodah" in Pesukei D'Zimrah on Erev Pesach and on Erev Yom Kippur, since on these days a person would not bring a todah offering.
Pieces of meat that became mixed up:
The Mishnah moves to a new section and leaves behind the issue of animals that became mixed up. Here we are dealing with pieces of meat: two cuts ready to be eaten, one from an asham and one from a shelamim. These cuts are too significant to be nullified in a mixture, and their identity is not lost. What, then, should he do?
In this case, the matter is simple: he eats them according to the stringencies of the asham - by kohanim only, in the Temple courtyard, and for one day. Likewise, if meat that is eaten for one day, like an asham, became mixed with meat eaten for two days, like a shelamim - he eats all of it in one day, and as a result, the time limit for eating neither of them has passed. He eats them according to the stringencies of both, and this is straightforward.
There is no great novelty in this line, and its point is this: The first part of the Mishnah rejected the possibility of treating the two animals according to the stringencies of both, because with whole animals there is an alternative solution - they graze until they develop a blemish, are redeemed conditionally, and he starts over. However, once they have become pieces of meat, there is no other way: if he waits until tomorrow, everything will become notar. Therefore, he will eat it all today, so that nothing goes to waste and he does not violate the prohibition of leaving meat overnight. He eats it stringently to ensure that the cut with a shorter time limit or more restricted consumption, because it is kodesh kodashim, will be eaten according to its stringencies. There is no problem with this either, and this is the halachah.
In summary: In this Mishnah we learned that an asham that became mixed with a shelamim - even though their blood service is identical - is not resolved by treating them according to the stringencies of both, because "ein mevi'in kodashim leveis hapesul" - we do not bring holy offerings to a state of invalidation: we do not reduce the allowed eaters and the time for eating in a way that will cause the meat to become notar. Therefore, according to the Sages, and this is the halachah, they graze until they develop a blemish and are redeemed. We discussed the practical halachic application of this rule - the prohibition against bringing a todah offering on the eve of Pesach and on the eve of Yom Kippur, and the custom of skipping "Mizmor Letodah" on these days. In contrast, with pieces of meat that became mixed together, which have no alternative solution, he eats them according to the stringencies of both in one day.