Charles Spurgeon Commentary Leviticus 16:15

"Then shall he kill the goat of the sin-offering, that is for the people, and bring his blood within the veil, and do with his blood as he did with the blood of the bullock, and sprinkle it upon the mercy-seat, and before the mercy-seat:" — Leviticus 16:15 (ASV)

Twice, you see, is the holy place thus sprinkled, first with the blood of the young bull, and then with that of the goat.