פירוש על זבחים 11:3

נתז מן הצואר –[from the neck] of the animal on the clothing, it does not require washing. As it is written (Leviticus 6:20): “and if its any of [its blood] is splattered,” I didn’t say other than that that whichis appropriate for sprinkling (i.e., was received in a pot).

If [blood] spurted [direct] from the [animal's] throat onto a garment, it does not require washing.
From the horn or from the base [of the altar], it does not require washing.
If it spilled out on to the floor [of the Temple] and [the priest] collected it, [and then it splattered onto a garment] it does not require washing.
Only blood which was received in a vessel and is fit for sprinkling requires washing.
If [the blood] spurted on to the hide, before it was flayed, it does not require washing.
[If it spurted] after it was flayed, it requires washing, the words of Rabbi Judah. Rabbi Elazar says: even [if it spurted on the skin] after it was flayed [it does not require washing].
Only the place of the blood requires washing.
And whatever is eligible to contract uncleanness,
And whatever is fit for washing.
Sections one-four: In section four the general rule that explains the first three sections of the mishnah is stated. The blood which if spilled on a garment requires the garment to be washed is only blood that was in a vessel and was fit for being sprinkled on the altar. In other words, totally valid blood, ready to be spilled onto the altar, contaminates the garment, because that’s not where the blood is supposed to be. But if the blood was not valid blood in a vessel, the garment need not be ritually washed.
The mishnah lists three such possibilities.
1) Blood which splatters directly from the neck of the animal onto the garment. Since it is not in a vessel, the blood doesn’t contaminate the garment.
2) If the blood was already spilled on the horn or the base of the altar, and then it gets on the garment, the blood doesn’t contaminate. This blood has already fulfilled its purpose and therefore it no longer contaminates.
3) If it had spilled onto the floor of the Temple, it can no longer be sprinkled onto the altar. Since it is no longer eligible for the altar, it doesn’t contaminate.
Section five: Before the hide is flayed from the animal, it is not a “garment” and not even in a state from which it can become a garment. Therefore, if blood spills on it, it is not contaminated.
Section six: According to Rabbi Judah, once it has been flayed, the hide is close enough to a garment, that it can become contaminated by the hatat blood. Even though a hide usually cannot become impure until it has been processed, if one should decide to use it as a garment in its current state, it would become susceptible to impurity. [We will learn more about this when we learn Seder Toharot]. Therefore, Rabbi Judah says it does require washing.
Rabbi Elazar says that since it is not at this moment susceptible to impurity, it does not require washing.
Section seven: The entire garment does not require washing, just the point that came into contact with blood.
Section eight: Only a garment that is susceptible to impurity must be washed. This would seem to exclude a piece of cloth so small that it can no longer become impure.
Section nine: Finally, if the garment cannot be washed, for instance a garment made of wood (I know, sounds weird), then it doesn’t require washing. The Torah only requires that washables be washed.

מן הקרן – [from the horn] of the altar.

ומן היסוד [from the foundation] – from the remnants that are appropriate to be spilled on the foundation, and even though they were not yet spilled, for after the giving of the blood is performed, the remanans do not require washing, as it is written (Leviticus 6:20): “[you shall wash] the besplattered part,” except fro that which already had been splattered of its blood.

אלא הדם שנתקבל בכלי – what is the reason that this is stated? For what reason that if it (i.e., the blood) is spilled on the floor and collected that it does not require washing but rather [only] the blood that was received in a utensil.

וראוי להזאה – to exclude receiving less than what is needed for sprinkling in this vessel, and less than what [is needed] for sprinkling in that [other] vessel but afterwards he mixed them, they are not holy and do not require washing.

עד שלא הופשט אין טעון כבוס (before it is flayed, it does not require washing) – as it is written (Leviticus 7:20): “[and if any of its blood is splattered] upon a garment,” just as a piece of clothing is susceptible to receiving ritual impurity, for one does not have a small piece of clothing whose name is “clothing” that is not susceptible to receive ritual impurity if he thought of it as a utensil as it was, even all that are susceptible to receive ritual impurity, and from when it is flayed, it is susceptible of receiving ritual impurity, if he thought of it to make it a covering of the chariot or to cover with it the bed and he doesn’t require the trimming of the ends of the skin.

אף משהופשט (even from when the hide is taken off) – all the while that it was not mended to be a utensil.

אין טיון כבוס – that we require something that is susceptible to ritual impurity, that is not missing even intention/thought.

אלא מקום הדם – and not the entire garment.

וראוי לקבל טומאה – and even though it is lacking intention. And asl long it would not be lacking work. But the anonymous section is according to Rabbi Yehuda, and such is the Halakha.

וראוי לכבוס – to exclude a wooden utensil. For even though it is susceptible to receive ritual impurity, it is not appropriate for washing, it is a mere scraping thing, and is not something washable.