We are going to elaborate on the Tumah (ritual impurity) of a person who is involved in burning these Korbanot (offerings) that we mentioned in the previous Mishnah. These are the inner Chataot (sin offerings), the ones that are burned inside the Heichal (sanctuary), or whose blood is poured inside the Heichal rather than on the outer Mizbeach (altar). We will elaborate on who becomes Tameh (ritually impure).
After they applied the blood and the Eimurim (portions burned on the altar) of these Chataot, they would carry them out of Yerushalayim. They would hang them by poles. The ones carrying the carcass of the Korban who were in front walked out of the walls of Yerushalayim. But the ones behind, carrying the pole, had not left yet. The ones in front become Tameh, along with the garments they are wearing. But the ones in the back do not make their garments Tameh until they themselves go out of the courtyard. When both groups have gone out of the courtyard, both the ones in front and the ones in back become Tameh, and they also make the garments they are wearing Tameh.
Rabbi Shimon says that you do not become Tameh by leaving the city, the walls of Yerushalayim, when you are involved in the process. You actually have to be involved in burning the Korban. You have to make sure that it catches fire. When you are involved in the actual burning of the Korban, that is when you become Tameh—but only when the majority of the carcass has caught fire. But once the meat is fully charred, someone might want to add fire to it and continue burning it past that point. If they burn it past that point, it would not make the garments Tameh. It only makes them Tameh until it is fully burned. But once it is fully burned, there is nothing to add; it is already considered fully burned. If you add to it, it does not affect your Tumah status.