John Calvin Commentary Leviticus 4:5

"And the anointed priest shall take of the blood of the bullock, and bring it to the tent of meeting:" — Leviticus 4:5 (ASV)

And the priest that is anointed shall take. It is well known that the prescriptions here regarding the sprinkling of blood, its pouring out, and the burning of the fat and the kidneys, are the same as in the other sacrifices. The comparison in the 10th verse sufficiently proves that the ordinary forms were observed in other particulars.

But since it might seem absurd that the priest, who was himself guilty, should come before God to perform the office of reconciliation, it was necessary to prescribe the details more accurately to remove any doubt.

Therefore, although he was unworthy to approach God, yet, because the law of the priesthood was inviolable, he was admitted to the discharge of his duties, for it was not lawful for more mediators to be appointed. Then, so that more reverence would be paid to the rites of the Law, and so that people would seek no other way of reconciliation, God extended His grace to the priest's fault.

The blood was sprinkled before the Lord so that the people might learn that through the sight of the sacrifice, sins were hidden and buried, so as to come no more into remembrance before God. But the rest of the blood was poured before the altar because it was holy and therefore must by no means be cast elsewhere like anything profane.