The Jewish sages note that the word retzach applies only to illegal killing (e.g., premeditated murder or manslaughter) - and is never used in the administration of justice or for killing in war. Hence the KJV translation as "thou shalt not kill" is too broad.
Since man is made in the image of God, his life is infinitely precious, and only God Himself has the right to give and take life. In the Mishnah it is written, "Why was only one man (i.e., Adam) created by God? - to teach that whoever takes a single life destroys thereby a whole world; and whoever saves one life, the Scripture accounts it as though a whole world had been saved (Sanhedrin 4:5).
But murder can be figurative as well as literal. The Talmud notes that shaming another publicly is like murder, since the shame causes the blood to leave the face. Moreover, gossip or slander are considered murderous to the dignity of man. The Pirkei Avot (Ethics of the Fathers) states, "The evil tongue slays three persons: the utterer of the evil, the listener, and the one spoken about…" Yeshua our LORD also linked the ideas of our words and attitudes with murder (see Matt. 15:19).