Genesis 9:5-6

"And surely your blood, the blood of your lives, will I require; at the hand of every beast will I require it: and at the hand of man, even at the hand of every man's brother, will I require the life of man. Whoso sheddeth man's blood, by man shall his blood be shed: for in the image of God made he man."

The change of person in Genesis 9:6 should not be disturbing, such is a phenomenon in the sacred writings found frequently in the Minor Prophets. Also the words, "In the image of God made he man," could be understood as an explanatory comment added by the inspired author of Genesis.

This whole passage may be viewed as God's precautionary action taken against the possibility of the recurrence of the universal physical violence that preceded the Flood. It is significant to note that this represents a change in the action of God Himself when He spared Cain, following the murder of his brother Abel. Cain's fear that someone would kill him (Genesis 4:14) shows that even he realized that his crime deserved death, hence, the fear that gripped his evil heart. But with the establishment of this law, God had seen enough of such leniency. Henceforth, the murderer would receive the retribution that his crime deserved. Capital punishment for murderers is a law here instituted by God Himself. The just application of such a law would necessitate the creation of a judiciary with power to exonerate those who were inadvertently guilty in a technical sense, but whose lives should be spared, as later formalized in the law of Moses in the establishment of the cities of refuge. The germ of government is also in this.

"By man shall his blood be shed ..." "This is not merely a permission legalizing, but an imperative command enjoining capital punishment."[9] Only God has the right to take life, but in this commandment, it is clear that, "When God commands man to execute murderers, He delegates this task to him, and it becomes his God-given responsibility[10] to do it. The repeal of capital punishment by many states today is not merely a mistake, it is a VIOLATION of God's law. The unjustified leniency of the judiciary in our own times could not possibly have any different effect than did God's leniency in the case of Cain. If any human society would like to invite the return of universal violence that precipitated the Flood, they could choose no quicker way to do it than by their rejection of God's commandment regarding murderers.

Keil called the divine order to execute murderers a command "that laid the foundation of all government ... a barrier against the supremacy of evil."[11] Right here is also the explanation for two DIFFERENT words in the Hebrew Scriptures for killing. They are [~ratsach] which means murder, and [~harag] which means put to death. [~Ratsach] is in the Decalogue, "Thou shalt not kill"; and the other is in Deuteronomy 13:9: "Thou shalt surely kill ([~harag]) him," referring to a legal execution. It is gross ignorance that tries to find in the Bible a prohibition of capital punishment, for it is precisely there that one reads the Divine institution of it and the unqualified order for men to enforce it. Of course, the manner of the enforcement of such a commandment was not prescribed here at a time prior to the establishment of human government, and that is the reason the next of kin under the patriarchal dispensation was given the responsibility, such an individual being called "the avenger of blood." In our own times the police authority of the central government is charged with the task, but in both instances, "The powers that be are ordained of God" (Romans 13:1). These verses are the account of such powers being ordained.