Zevachim Chapter 9, Mishnah 6. The Mishnah begins with the word **"vechulam"** - all those things mentioned in the previous Mishnah, which do not belong on the altar in their own right but come as secondary to something else. We already learned in Mishnah 2 about things that do not need to go up on the altar, but if they went up, they remain up there. Here, we are discussing a case where they already went up, and afterward **"paku me'al gav hamizbeach"** - they descended from the altar due to the force of the fire's heat.
Two explanations of the term "paku":
An expression of jumping and flying - this is how the Rambam explains it: The item flies and jumps off the altar. When items containing moisture are placed on a large fire, the liquid inside heats up and turns into steam, and due to the eruption, the item might jump from its place.
An expression of splitting - this is how Tosafos and others explain it: Splitting, like the splitting and chopping of wood. We similarly find in a Mishnah in Tractate Sukkah that the worn-out garments of the kohanim were **"mafki'in"** - they would tear them and make wicks out of them to light the large menorahs in the Beis Hamikdash. From here we see that **"mafki'in"** is an expression of tearing and opening.
We find that through the fire, these items are propelled off the top of the altar, and regarding this, the Mishnah states **"lo yachazir"** - there is no obligation to return them. One has permission to return them, but he is not obligated to do so. Even though we learned earlier the rule of Ulla, that from the moment an item begins to burn in the fire it becomes the "bread of the altar", the food of the altar, and belongs to it - here, once it has begun burning properly and not just a minor burning, and most of it was consumed, there is no longer an obligation to return it, even though it is the bread of the altar.
Similarly, a coal that popped off the top of the altar: The same law applies to a coal that jumped off the top of the altar onto the floor of the Courtyard - there is no need to return it to its place, since it has already burned. However, if it jumped from the arrangement of wood, from the main bonfire, onto the broad surface of the altar, he is certainly obligated to push it back into the arrangement of wood. But once it has descended off the altar to the floor, there is no need for this, and he has permission but no obligation to return it to the arrangement on the altar.
A limb that popped off the top of the altar:
Before we enter into the body of the Mishnah, let us introduce a rule: In the Beis Hamikdash, the entire night is inherently considered as one single time period, and we do not differentiate between the first half and the second half of the night. This rule applies primarily to the burning of the fats and limbs, which the Torah permits to be burned all night until morning. Wherever we find a halachah concerning midnight, it is only a rabbinic law. Regarding the Pesach offering, there is a dispute in the Gemara and among the Tanna'im, and the halachic authorities dispute this as well, whether the obligation to eat it until midnight is rabbinic - but this is an exception, and generally, the night is not divided into parts.
In light of this, our Mishnah comes to teach a novel concept, that in one specific area there is a difference, and this is based on the verses: The verse dealing with the burning of the fats and limbs speaks of leaving them all night until morning. Seemingly, there is an extra phrase here, since "all night" inherently includes until morning, so why were the words "until morning" added? From here they expounded that in this context, the night has two halves.
Before we examine that context, we must clarify the three states:
Not completely burned: There is an obligation to burn the limbs and the fats completely, and one has all night to do so. Therefore, if a limb or fat was not completely burned - he is obligated to return it to the altar, and there is no difference between before midnight and after midnight, only that he must do so before dawn.
Completely burned: According to everyone, once the item has been completely burned and has become like charcoal, there is no obligation to return it to the altar. Once it is burned - it is finished, its mitzvah has been performed, and this applies at whatever time this occurred during the night, whether before midnight or after midnight.
The intermediate case: This is what our Mishnah deals with, and although it is not explicitly stated in it, the Gemara explains that this is a case where the item waiting to be burned on the altar dried out completely and became like wood, with no moisture remaining in it, but it did not completely blacken inside and out like charcoal, and therefore it still has more burning to do. In this case, the Mishnah distinguishes: If it jumped off by itself before midnight - it must be returned; after midnight - it does not need to be returned.
The law of me'ilah:
Me'ilah is the unlawful use of consecrated property, things that are consecrated to Hashem and to the Holy One, Blessed be He. The rule is that once the mitzvah has been performed and there is nothing more to do with that item, it loses its status as consecrated to Hashem, and the law of me'ilah no longer applies to it. The famous example of this is the water channel we spoke about earlier, the amah: The blood went in there, and once it flowed and they brought it out, they would sell this blood to local farmers to fertilize their fields. Seemingly, how could this be possible - isn't this the blood of offerings, and does me'ilah not apply to it? Rather, once the mitzvah was performed and there was nothing more to do with it, it lost its consecrated status and became the property of the Beis Hamikdash, and they would sell it for profit.
The same applies here: if the limbs were already burned and there is no longer a need to burn them, their mitzvah is completed and they are no longer subject to me'ilah. However, if they still have a mitzvah to be fulfilled, one who derives personal benefit from them has committed me'ilah. If he did so unintentionally, he pays the principal value, adds a fifth, and brings an asham me'ilos (me'ilah guilt-offering).
Thus, the laws of the Mishnah emerge in three situations:
If a limb popped off the altar, or a piece of it or more, and it is not yet completely burned - it certainly must go back up to be completely burned, and it is subject to me'ilah, since it has not completed its mitzvah.
If it blackened and became like a coal - it is completely finished, and there is no point in returning it even before midnight, and there is no me'ilah in it, as it has already fulfilled its mitzvah.
The intermediate case, where it dried out like wood and did not blacken completely along its length and width - before midnight it must go back up, and therefore it is still subject to me'ilah, since it has not completed its mitzvah; after midnight it does not need to go back up, and since its mitzvah has been fulfilled - it is no longer subject to me'ilah.
And in the words of the Mishnah: "Eivarim shepaku me'al gabei hamizbe'ach" - if limbs popped off the altar. "Kodem lachatzos" - before midnight, and in that intermediate state where they did not yet completely blacken but dried out like wood. "Yachazir" - he is obligated to return them. "Umo'alin bahen" - and if he does not return them and derives benefit from them, since they have not completed their mitzvah, the prohibition of me'ilah applies here. "Le'achar chatzos" - after halachic midnight, and they dried out like a piece of wood. "Lo yachazir" - there is no longer an obligation to return them, as their mitzvah has been done. "Ve'ein mo'alin bahen" - the law of me'ilah no longer applies to a piece of meat that was mostly burned.
These are the words of the Mishnah on this matter.