Genesis 9:5 - Ellicott's Commentary On The Whole Bible

Your blood of your lives.... — This verse should be translated: “And surely your blood, which is for your souls, will I require (i.e., avenge); from every beast will I require it, and from man: even from a man’s brother will I require the soul of man,” as from Cain. “Your blood, which is for your souls,” means that it is the means for the maintenance of the animal life within them. As it is, then, the support of man’s life, au animal which sheds it becomes guilty, and must be slain; and still more must those animals be destroyed which prey upon man. Thus there is a command given for the extirpation of the carnivora at the time when the more peaceful animals had just been saved. The last clause literally is... at the hand of man, at the hand of one that is his brother, will I require the soul of man. This has nothing to do with the avenger of blood. The near kinsman is here the murderer, and the commandment requires that even such an one should not be spared.