Zevachim Chapter 4, Mishnah 4 - Part Two. In this part, the Mishnah discusses the consequences of an intention outside its proper time in the inner chatas offerings: those five offerings whose blood is brought inside and placed on the inner altar - in the Kodesh and even in the Kodesh Hakodashim - and not on the outer altar in the courtyard.
The five inner chatas offerings are:
The he-goat for Hashem of Yom Kippur - as opposed to the he-goat for Azazel, which is like its twin.
The bull of the kohen gadol of Yom Kippur - which he brings for himself and for his household.
The bull for an unknown communal sin - which the Sanhedrin (or the public) brings when the Sanhedrin erred in a ruling regarding a matter for which one is liable for kares, and the public acted according to them.
The he-goat for idol worship - the same matter as the bull for an unknown communal sin, except that when the ruling they erred in pertained to idol worship, a he-goat is brought instead of a bull.
The bull of the anointed kohen - when the anointed kohen gadol ruled for himself and erred in a matter for which one is liable for kares: instead of a regular chatas, he brings a special bull whose blood is placed on the inner altar.
This blood is placed on the golden altar, which is the inner altar. Similarly, the blood is sprinkled toward the paroches, the curtain separating the Kodesh and the Kodesh Hakodashim, and in the two offerings of Yom Kippur, blood is sprinkled even inside the Kodesh Hakodashim itself. Thus, there are multiple placements of blood here.
In this way, the inner offerings differ from those of the outer altar: on the outer altar, even if any amount of blood reached the proper place on the altar, one placement is sufficient after the fact to validate the offering. Not so with the inner altar - in these five chatas offerings, all the placements of blood must be performed properly, and all of them are essential.
This raises a possibility that did not exist with the outer altar. On the outer altar, the first placement is the determining one, and if an intention outside its proper time occurred after it - at the time of the second placement - it no longer has significance, since the validating placement has already been done. But on the inner altar, where multiple blood placements are required and all are essential, it is possible that some of them will be performed with proper intention and some with invalid intention.
It is understood that any invalid intention during one of the placements invalidates the offering. The question is this: if he had only an intention outside its proper time, without any other invalidating intentions, but this intention was present during one or more of the blood placements and not all of them - does the offering become piggul, rendering one who eats its meat liable for kares?
The language of the Mishnah:
"Kol hanitanin al mizbach hapenimi" - those five offerings whose blood is placed on the inner altar, "she'im chisar achas min hamatanos lo kiper" - that if he omitted even one placement, or did not perform it properly due to an invalid intention, the offering is ineffective. "Lefichach im nasan kulan kesiknan ve'achas shelo chesiknah" - he gave all the placements properly, and one of the blood placements improperly, having an intention outside its proper time during that one alone - such as thinking to burn the eimurim of the chatas tomorrow, at a time that is not proper - then the offering is "pasul, ve'ein bo kares": the offering is indeed invalidated, but one who eats from it is not liable for kares.
The reason for this is that the Tanna and the Sages hold that we do not create piggul with half a matir. When an intention outside its proper time was on only a part of the matir - meaning on some of the blood placements and not on all of them - it does not make the offering piggul to incur liability for kares.
It is worth noting that Rabbi Meir holds in Tractate Menachos that we do create piggul with half a matir, and according to his view - unlike our Mishnah - even an intention during just one placement makes the offering piggul, and one who eats from it is liable for kares. However, the halachah follows the view of the Sages, like the anonymous Mishnah before us: unless he thought during all the blood placements that he would burn the eimurim outside its proper time, the offering is not piggul - and even though it is invalidated, one who eats from it is not liable for kares.
In summary: In this part we learned the law of the five inner chatas offerings, in which all the blood placements are essential, unlike the outer altar where one placement is sufficient after the fact. From this we learned that an intention outside its proper time during some of the placements invalidates the offering, but does not make it piggul - since we do not create piggul with half a matir - and the halachah is decided in this way according to the view of the Sages and not like Rabbi Meir.