Mishnayos Kerisos Perek 3 Mishnah 4

ארבע חטאות – one is because of [eating] forbidden fat, and one is because of eating Holy Things while [in a state of] ritually impure, and one is because of a remnant/left over (i.e., part of an offering left over after the time permitted for it to be eaten), and one because it was on Yom Kippur, for we hold throughout the entire Torah, that a prohibition does not take effect upon another prohibition , these words refer to a mere prohibition, as for example, a person who consumes the carrion of n impure animal, he is not liable because of he carrion because it is a mere prohibition that is not inclusive, nor does it add [to the prohibition]. But here, a person who was from the outset ritually pure, he was prohibited to consume prohibited fat and permitted with the rest of the meat of Holy Things. If he became ritually impure, since he became prohibited as regards the rest of the pieces of the meat of Holy Things because of ritual impurity, he is prohibited also [to consume] the prohibited fat, even though he was forbidden from the outset, and that is, an inclusive prohibition, that the final prohibition includes and prohibits other things on a person that were permitted to him from the outset. But however, it doesn’t add a prohibition on a sacred object held in hand at the delivery of an oath, but rather on the person it adds a prohibition regarding other things, and whetting the appetite and measuring also for this in his prohibition. This forbidden fat becomes a left-over (i.e., after the time permitted for it to be eaten, which is a prohibition that adds, that ab initio for a regular Kohen, is prohibited but for the Most High is permitted, since when it became a left-over, added a prohibition on the piece [of meat] itself to be forbidden even to the Most High. But since the name of a left-over prohibition takes effect upon it to make it forbidden to the Most High, it also takes affect the title of left-over regarding an ordinary [Priest] to make it liable because of left-overs, even though that without this, it would be forbidden to the regular [Priest]. The [prohibition] of Yom Kippur occurs to it, since a prohibition was added regarding a person to prohibit him from [partaking of] non-consecrated things which were permitted to him prior to Yom Kippur, whetting the appetite and measuring for this prohibited fat of Holy Things explicitly to be liable for it because of the Day of Atonement.

ואשם אחד – the guilt-offering for misuse of consecrated articles that he benefitted from that which was consecrated [to the Temple] inadvertently. But even this prohibition adds on the sacred object that is held at the delivery of an oath, for prior to his sanctifying it, this forbidden fat was prohibited to eat, but permissible in deriving benefit, once it was sanctified, it becomes prohibited even for deriving benefit, and because the name of “dedicated to the Temple” takes effect on the forbidden fat to prohibit him from deriving benefit, it also takes effect to make him liable for eating it because he is benefitting from that which is dedicated to the Temple.

אם היה שבת והוציאו בפיו – while he was eating it [going from one domain to another].

חייב – [he is liable] also on he removal from one domain to another. Bur in the Gemara (Tractate Keritot 14a) it explains that this is what he said: If it was Yom Kippur that fell on the Sabbath and he took it out, he is liable for two [sins] on his removing it – because of the Sabbath and because of Yom Kippur, the two of them come as one, for at the time that he sanctified the day for Sabbath, he sanctified also for Yom Kippur. And just as there is an Eruv and removal [from one domain to another] for Shabbat, so too, there is an Eruv and removal [from one domain to another] on Yom Kippur. And the prohibition takes effect upon another prohibition with the prohibition at one time.

אינו מן השם – meaning to say the Tanna/teacher (i.e., Rabbi Meir) did not consider anything other than sin-offerings that come because of eating, but this is because of removal [from one domain to another].