Genesis 9:6

“Whoso sheddeth man’s blood, by man shall his blood be shed, etc.] That is, he that is guilty of wilful murder shall surely be put to death by the order of the civil magistrate; so the Targum of Jonathan, “by witnesses the judges shall condemn him to death,” that is, the fact being clearly proved by witnesses, the judges shall condemn “him to death,” that is, the fact being clearly proved by witnesses, the judges shall pass the sentence of death upon him, and execute it; for this is but the law of retaliation, a just and equitable one, blood for blood, or life for life; though it seems to be the first law of this kind that empowered the civil magistrate to take away life; God, as it is…”

“Whoso sheddeth man's blood . . . for in the image of God made he man--It is true that image has been injured by the fall, but it is not lost. In this view, a high value is attached to the life of every man, even the poorest and humblest, and an awful criminality is involved in the destruction of it.”

“- The Blessing of Noah 2. מורא môrā', “fear, reverence, awful deed.” חת chat, “dread, breaking of the courage.” Noah is saved from the deluge. His life is twice given to him by God. He had found grace in the sight of the Lord, and now he and his family have been graciously accepted when they approached the Lord with burnt-offerings. In him, therefore, the race of man is to be begun anew. Accordingly, as at the beginning, the Lord proceeds to bless him. First. The grant of increase is the same as at first, but expressed in ampler terms. Second. Dominion over the other animals is renewed. But some reluctance on their part to yield obedience is intimated. “The fear and dread of you.” These…”

“9:6 For God made human beings in his own image: The death penalty has a theological basis. God’s image gives humans a unique status and authority within creation (1:26-28). Since murder destroys a person made in God’s image, the ultimate penalty must be imposed on a murderer. See also Exod 21:23-25. We are not to pursue personal revenge (Rom 12:17-19) but are to uphold the justice of the “governing authorities” that God has established (Rom 13:1-7).”