Zevachim 39 - Blood at the Inner Altar
For these sacrifices all four blood applications were essential, and if the Kohen omitted one of them, he has not effected atonement. However, since all four applications thus work as a group, if the Kohen had the "beyond alloted time" intent during one of them, he has made the sacrifice invalid, but not to the point of rejection, and one who eats its meat does not incur being cut off from the people.
From where do we know this law? The Torah said, "He shall do to the blood of the communal-error bull as he would do to the blood of the bull of the High Priest." This phrase was unnecessary, and thus it teaches an additional law, that all blood applications are essential.
Art: Filippo Palizzi - Feeding Time
