Leviticus 17:4

And bringeth it not unto the door - As sacrifice was ever deemed essential to true religion, it was necessary that it should be performed in such a way as to secure the great purpose of its institution. God alone could show how this should be done so as to be pleasing in his sight, and therefore he has given the most plain and particular directions concerning it. The Israelites, from their long residence in Egypt, an idolatrous country, had doubtless adopted many of their usages; and many portions of the Pentateuch seem to have been written merely to correct and bring them back to the purity of the Divine worship. That no blood should be offered to idols, God commands every animal used for food or sacrifice to be slain at the door of the tabernacle. While every animal was slain in this sacrificial way, even the daily food of the people must put them in mind of the necessity of a sacrifice for sin. Perhaps St. Paul had this circumstance in view when he said, Whether therefore ye eat or drink, or whatsoever ye do, do all to the glory of God, I Corinthians 10:31; and, Whatsoever ye do in word or deed, do all in the name of the Lord Jesus, giving thanks to God and the Father by him. While the Israelites were encamped in the wilderness, it was comparatively easy to prevent all abuses of this Divine institution; and therefore they were all commanded to bring the oxen, sheep, and goats to the door of the tabernacle of the congregation, that they might be slain there, and their blood sprinkled upon the altar of the Lord. But when they became settled in the promised land, and the distance, in many cases, rendered it impossible for them to bring the animals to be slain for domestic uses to the temple, they were permitted to pour out the blood in a sacrificial way unto God at their respective dwellings, and to cover it with the dust; see Leviticus 17:13, and Deuteronomy 12:20, Deuteronomy 12:21.

Blood shall be imputed unto that man - Having poured out the blood improperly, he shall be considered as guilty of murder, because that blood, had it been properly and sacrificially employed, might have made atonement for the life of a man.