Genesis 9:5

But the blood of your lives I will I require of every animal which hath killed a man, I will require that it be put to death on his account. And from the hand of the human being, from the hand of the man who hath shed the blood of his brother, will I require the life of man.

AND SURELY YOUR BLOOD ‘LENAPHSHOTHEICHEM’ (OF YOUR LIVES) WILL I REQUIRE. This is as if it were written, your blood ‘naphshotheichem,’ [without the letter lamed], and meaning “your blood which is your lives.” This is similar to the verse, ‘Lechol’ (To all) the instruments of the tabernacle, [which means all the instruments needed for the tabernacle, the letter lamed in the word lechol being redundant]. So also, the third ‘l’Avshalom’ (to Absalom), [which means, “the third, Absolom,” the lamed in the word l’Avshalom is redundant].
It is possible to explain your blood ‘lenaphshotheichem’ as meaning benaphshotheichem (in your souls), for the life of all flesh, the blood thereof is all one with the life thereof. Likewise, And ye shall eat no manner of blood in all your dwelling places, ‘la’oph velabeheimah’ (to fowl and to cattle),, 7:26. which is to be explained as “in fowl or in beast.”
The correct interpretation is that Scripture is saying, “the blood which is the life in you I will require.” He is thus declaring that the blood is one with the life, and He intimates that one incurs the death penalty for spilling the blood upon which life depends, but not for spilling the blood of those limbs on which life is not dependent. Our Rabbis have expounded this verse as an injunction against suicide, the verse stating, “I will require your blood from your own souls.”

ואך את דמכם לנפשותיכם אדרוש, although I will not punish you for spilling animal’s blood, I will hold you responsible for shedding the blood of fellow human beings. Human beings, all human beings, are more precious to Me than the lives of animals. This retribution for spilling the blood of human beings may on different occasions be applied in different ways: It all depends on the worthiness of the person under attack or potential attack. If, for instance, the person deserves saving, the words מיד כל חיה אדרשנו ומיד אדם are meant in the preventive sense, i.e. G’d will save such a person’s life be it under attack from animals or from human beings. If, in the eyes of G’d, the person under attack does not deserve being saved from violent death, this still did not give the animals or other human beings the right to kill him. Therefore, in such instances, ipso facto, G’d will exact retribution from the killers.

This is the meaning of the apparently redundant words מיד איש אחיו אדרוש את נפש האדם, where the word אדרוש refers to the life of a human being that has already been killed. We find the word אדרוש in both senses depending on circumstances, compare Ezekiel 34,10. The emphasis on איש את אחיו, refers to G’d exacting such retribution from humans for killing humans, seeing that this is not their nature, or should not be their nature. He will not exact retribution from an animal which killed a human being who, in G’d’s eyes, had already forfeited its right to live.

אך את דמכם לנפשותיכם, even though I have permitted the blood of animals, i.e. you may kill animals, I have not permitted the animals to kill you, seeing that I have given them into your control, and not vice versa.

לנפשותיכם, the meaning of this word is that if an animal kills a human being it becomes guilty of death itself, unless I use the animal to exact retribution form wicked people, as in the case of the bears who killed the youngsters who had mocked the prophet Elisha (Kings II 20,23, or Kings I 13, entire chapter). [the fact that the lion had not touched the corpse of the man he had killed, showed that the lion had acted as G’d’s messenger, had not acted from impulse in order to still its hunger. Ed] Also in the תוכחה in Leviticus 26,22 G’d specifically announces that He would use the free roaming beasts as His agents to wreak vengeance of the Jewish people who had sinned deliberately and for a long period of time. Our sages (Bereshit Rabbah 34,13) explain the words דמכם לנפשותיכם, as a warning not to commit suicide (especially to people who thereby expect to escape G’d’s retribution) The message is that the person who killed himself will be held accountable in the hereafter. They said further that the word אך at the beginning of the verse excludes such apparent suicides as Chananyah, Mishael, and Azaryah, being prepared to become martyrs to demonstrate their faith in the G’d in heaven

מיד כל חיה אדרשנו, the offending animal which killed a human being will itself be killed by another animal. Even though the principle of reward and punishment is not generally applicable to any species other than the human species, seeing that only man possesses intelligence so that he can be held responsible for his sins, when animals attack human beings G’d did restrict their instincts, and holds them responsible for not respecting the צלם אלוקים, the divine image in which man has been created. Chabakuk 2,17 phrases this principle as ושד בהמות יחיתן, “the destruction of beasts will overwhelm you.” Moreover, when speaking of retribution, we read in Kings I 13,28 ולא שבר את החמור, “nor had it mauled the ass.” [this proved that when the lion had killed the man of G’d, it had acted as an instrument of G’d’s justice. Ed]

ומיד האדם, if man kills man, G’d reserves the right to exact retribution from him either in this life or in the hereafter.

ואך את דמכם לנפשותיכם אדרוש, “however for your own life-blood I will demand an accounting;” this is to be understood as an accounting for their death by people who deliberately strangle themselves as an act of suicide, avoiding the shedding of their blood in the process. B’reshit Rabbah, 34,13, explains the need for this verse as being that we might think that when Chananyah, Mishael and Azaryah, (Daniel chapter 3 where their Babylonian names are used) agreed to be thrown into a fiery pit, clearly committing suicide, albeit as an act of sanctifying the name of the Lord, this was forbidden also. The reason that this verse was introduced by the word: אך, was to exclude such suicides, even that of King Sha-ul, who did not want to give the Philistines the satisfaction of having killed a king who had been crowned with the approval of the Lord. (Samuel I 31,4) In both of these instances the victims did not execute themselves but were executed or meant to be executed by someone else. Committing suicide with one’s own hands is an absolute no no. According to the opinion of Rabbi Shimon bar Avraham, also known as אוכמן, the Rabbis did not make allowances for what King Sha-ul had done. There is a true story of a Rabbi, who at the time of persecutions of Jews practicing their faith, personally killed many young Jewish children in order to forestall the Christians from raising them in the Christian faith. One of his Rabbinical colleagues was very angry at that Rabbi on that account, referring to him as a murderer. The first Rabbi did not heed the second Rabbi’s warning not to become a murderer. Thereupon the Rabbi opposed to killing the infants said that if he had been right, his colleague would die a violent and painful death. Not only did the gentiles seize and kill that Rabbi-(who had killed the infants), but they stripped off his skin and placed sand between it and his flesh. Shortly thereafter, the decree forbidding the Jews to practice their faith was cancelled. If the first Rabbi had not killed all the infants, they would have been saved when the decree was cancelled.