For if the blood of bulls and of goats, and the ashes of an heifer sprinkling the unclean, sanctifieth to the purifying of the flesh: 14 How much more shall the blood of Christ, who through the eternal Spirit offered Himself without spot to God, purge your conscience from dead works to serve the living God? – Hebrews 9:13,14
Notice that in the slaughter of the heifer (in Numbers 19), blood was presented and sprinkled towards the Holy Place seven times, though it came not actually into it. So in the Atonement through which we find peace of conscience there is blood, for “without shedding of blood there is no remission of sin.” That is a settled decree of the Eternal Government, and the conscience will never get peace till it understands the mystery of the blood. We need not only the sufferings of Christ, but the death of Christ, which is set forth by His blood. The Substitute must die. Death was our doom and death for death did Christ render unto the eternal God. It is by a sense of our Lord’s substitutionary death that the conscience becomes purged from dead works.
Furthermore, the heifer itself was offered. After the blood was sprinkled towards the tabernacle by the priestly hand, the victim itself was utterly consumed. Read now our text—“Christ, who through the eternal Spirit offered up Himself without spot unto God.” Our Lord Jesus Christ gave not merely His death, but His whole Person, with all that appertained to it, to be our substitutionary Sacrifice. He offered Himself, His Person, His Glory, His holiness, His life, His very Self in our place. But, Brothers and Sisters, if a poor heifer, when it was offered and consumed, made the unclean man clean, how much more shall we be cleansed by Jesus, since He gave Himself, His glorious Self, in whom dwelt the fullness of the Godhead bodily? Oh, what a Sacrifice is this! ~ C.H. Spurgeon
https://www.blueletterbible.org/comm/spurgeon_charles/sermons/1481.cfm