Leviticus 16:11-14

Aaron shall bring the bull of the sin offering, which is for himself, and shall make atonement for himself, and for his house, and shall kill the bull of the sin offering for himself. And he shall take a censer full of burning coals of fire from the altar before the LORD, and two handfuls of sweet incense beaten small, and bring it within the veil. And he shall put the incense on the fire before the LORD, that the cloud of the incense may cover the mercy seat that is over the testimony, so that he does not die. And he shall take of the blood of the bull, and sprinkle it with his finger on the mercy seat on the eastern side, and before the mercy seat he shall sprinkle from the blood with his finger seven times.