The Prophet said: "Do not revert to disbelievers after I am gone, striking the necks of one another (killing one another)."
Sunan an-Nasa'i Book 37, Hadith 160
← Previous Hadith The Messenger of Allah said: "If two Muslims confront each other with swords and one of them kills the other, then the killer and the slain will both be in Hell." A man said: "O Messenger of Allah, (we understand about) the killer, but what about the one who is killed?" He said: "He wanted to kill his companion."

Sunan an-Nasa'i Book 37, Hadith 159 Next Hadith → "The Messenger of Allah said: 'Do not revert to disbelievers after I am gone, striking the necks of one another (killing one another). No man is to be punished for the sins of his father, or for the sins of his brother.'"

Sunan an-Nasa'i Book 37, Hadith 161