At the very threshold of the Mosaic dispensation stands the sacrifice of the Paschal Lamb connected with the redemption of Israel, and which in many respects must be regarded as typical, or rather anticipatory, of all the others. But there was one sacrifice which, even under the Old Testament, required no renewal. It was when God had entered into covenant relationship with Israel, and Israel became the ‘people of God.’ Then Moses sprinkled ‘the blood of the covenant’ on the altar and on the people. On the ground of this covenant-sacrifice all others rested.3 These were, then, either sacrifices of communion with God, or else intended to restore that communion when it had been disturbed or dimmed through sin and trespass: sacrifices in communion, or for communion with God. To the former class belong the burnt-and the peace-offerings; to the latter, the sin- and the trespass-offerings. But, as without the shedding of blood there is no remission of sin, every service and every worshipper had, so to speak, to be purified by blood, and the mediatorial agency of the priesthood called in to bring near unto God, and to convey the assurance of acceptance.

Edersheim, A. (2003). The Temple, its ministry and services as they were at the time of Jesus Christ. (pp. 108–109). Bellingham, WA: Logos Bible Software.