Leviticus 16:14-15

Then he must take some of the blood of the bull, dip his finger in it, and sprinkle it on the east side of the atonement cover. He must sprinkle blood seven times with his finger in front of the atonement cover. “Then Aaron must slaughter the first goat as a sin offering for the people and carry its blood behind the inner curtain. There he will sprinkle the goat’s blood over the atonement cover and in front of it, just as he did with the bull’s blood.