"He who thinks that the living entity is the slayer or that he is slain does not understand. One who is in knowledge knows that the self slays not nor is slain." [Bg. 2.19]
“For the soul there is neither birth nor death at any time. He has not come into being, does not come into being, and will not come into being. He is unborn, eternal, ever-existing and primeval. He is not slain when the body is slain.” [Bg. 2.20]
So, in different ways, Krsna is trying to convince us how the soul is immortal. Different ways. Ya enam vetti hantaram [Bg. 2.19]. When there is fight, so if one is killed or... So Krsna says that if one thinks that "This man has killed this man," so, or "This man can kill this man," this kind of knowledge is not perfect. Nobody kills nobody. Then the butchers, they may say that "Then why do you complain that we are killing?" They're killing the body, but you cannot kill when there is injunction "Thou shall not kill." That means you cannot kill the body even without sanction. You cannot kill. Although the soul is not killed, the body is killed, still you cannot kill the body without sanction. That is sinful. For example, that a man is living in some apartment. So some way or other you drive him away from that, illegally, you drive him away. So the man will go out and will take shelter somewhere. That's a fact. But because you have driven him away from his bona fide position, you are criminal. You cannot say, "Although I have driven away, he'll get some place." No. That's all right, but you have no power to drive him away. He was in his legal position to live in that apartment, and because you have forcibly driven him away you are criminal, you should be punished.
73/08/25 London, Bhagavad-gita 2.19-20