Zevachim 93B

הא תו למה לי? מה טעם קאמר: מה טעם נשפך על הרצפה ואספו אין טעון כיבוס ⁠– לפי שאין טעון כיבוס אלא דם שנתקבל בכלי וראוי להזייה.

With regard to the statement that only blood that was collected in a vessel and is fit for sprinkling requires the laundering of the garment on which it sprayed, the Talmud asks: Why do I also need this? After all, it was already taught that if blood spilled from the neck onto the floor before it was collected in a vessel, and it sprayed on a garment, the garment does not require laundering. The Talmud answers: This is not an additional halakha, but rather the Mishnah is saying: What is the reason? What is the reason that if the blood spilled from the neck onto the floor before it was collected in a vessel, and the priest collected it and it sprayed on a garment, the garment does not require laundering? This is because it is only with regard to blood that was received in a sacred vessel and is fit for sprinkling that the garment requires laundering.

ראוי להזאה ⁠– למעוטי מאי? למעוטי קיבל פחות מכדי הזייה בכלי זה ופחות מכדי הזייה בכלי זה.

§ The Mishnah teaches: It is only with regard to blood that was received in a sacred vessel and is fit for sprinkling that the garment requires laundering. The Talmud asks: As it was already taught that when disqualified blood is sprayed on a garment, it does not require laundering, this reiteration serves to exclude what? The Talmud answers: It serves to exclude the case where a priest received less blood than is sufficient for sprinkling in this vessel, and less than is sufficient for sprinkling in that vessel, and then he mixed together the blood from the two vessels. In such a case, even though the combined amount is now enough for sprinkling, the blood did not become fit for sprinkling.