Commentaries:
Some people vehemently oppose capital punishment for murderers. They view it as nothing more than legalized murder committed by the state and a punishment that has no deterrent effect. But how does God, who should be our final authority, weigh in on this matter? His instruction to Noah, upon leaving the ark following the Flood, covers Genesis 8:15—Genesis 9:17, part of which involves governments of men: "Surely for your lifeblood I will demand a reckoning; from the hand of every beast I will require it, and from the hand of man. From the hand of every man's brother I will require the life of man" (Genesis 9:5).
Although man has a moral responsibility to God—"render . . . to God the things that are God's"—we must also give a reckoning to men—"render . . . to Caesar the things that are Caesar's" (Matthew 22:21). God has thus delegated to human governments certain areas of His authority in which man obeys God through subjection to his fellow men. God instituted human government to regulate the corporate relationship of man to man, and this includes the authority to take life as punishment for crimes involving murder.
One of the highest responsibilities of government is the protection of life. From this commitment to protect the lives of the innocent arises the very serious responsibility of capital punishment. Humans are not only commanded not to murder, but they are also not to avenge murder. That responsibility falls on the state.
John W. Ritenbaugh
The Sixth Commandment (Part One) (1997)
Though we see only a small, essential portion of what God instructed Noah about life after the Flood, this context is enough to know that He is providing a basis for the establishment of laws regulating social conduct.
Why is that necessary? The reason given is because man is in the image of God. Man is being prepared for something far exceeding that of any other part of God's creation.
Man, like God, is a being who can make choices. Unlike the rest of the physical creation, man is not a creature of instinct, reacting according to preset patterns, but one who must analyze and choose to do the right as stipulated by law.
Animals do not react by understanding and analyzing law and then making a rational decision. Yes, they react to laws, but they are reacting to ones set within their brains, instinctive patterns according to which they must react.
Man does not react instinctively. Because he has mind, he is free to do the wrong thing! But he is also free to do the right thing, as stipulated by law.
John W. Ritenbaugh
Other Forerunner Commentary entries containing Genesis 9:5:
Leviticus 2:1