Matthew Poole and continuators on Exodus 29:36

36 And thou shalt offer every day a bullock for a sin-offering for atonement : and thou shalt cleanse the altar, when thou hast made an atonement for it, and thou shalt anoint it, to sanctifie it.

As well for the Priests, as for the Altar, both which as they were or might be polluted, so they needed the sprinkling of this blood to sanctifie them, to shew that all persons and things were fitted for Gods service and accepted by him onely for and thorough the blood of Christ.