Leviticus 16:20

“The priest shall take some of the blood from the sin offering and put it on the door posts of the house, on the four corners of the ledge of the altar, and on the posts of the gate of the inner court.

“And thus you shall do on the seventh day of the month for everyone who errs or is simpleminded; so you shall make atonement for the house.

but into the second, only the high priest enters once a year, not without taking blood, which he offers for himself and for the sins of the people committed in ignorance.