Leviticus 16:14-15

14He shall take some of the bull’s blood and sprinkle it with his finger on the east side of the mercy seat; also in front of the mercy seat he shall sprinkle some of the blood with his finger seven times.

15“Then he shall kill the goat of the sin offering that is for [the sins of] the people and bring its blood within the veil [into the Most Holy Place] and do with its blood as he did with the blood of the bull, and sprinkle it on the mercy seat and in front of the mercy seat.