I was with the Prophet (ﷺ) when a man who was a murderer and had a strap round his neck was brought to him.

He then called the legal guardian of the victim and asked him: Do you forgive him?

He said: No. He asked: Will you accept the blood-money? He said: No. He asked: Will you kill him? He said: Yes. He said: Take him. When he turned his back, he said: Do you forgive him? He said: No. He said: Will you accept the blood-money? He said: No. He said: Will you kill him? He said: Yes. He said: Take him. After repeating all this a fourth time, he said: If you forgive him, he will bear the burden of his own sin and the sin of the victim. He then forgave him. He (the narrator) said: I saw him pulling the strap.

The tradition mentioned above has also been transmitted by 'Alqamah b. Wa'il through a different chain of narrators and to the same effect.

A man brought an Abyssinian to the Prophet (ﷺ) and said: This man has killed my nephew. He asked: How did you kill him? He replied: I struck his head with axe but I did not intend to kill him. He asked: Have you some money so that you pay his blood-wit? He said: No. He said: What is your opinion if I send you so that you ask the people (for money) and thus collect your blood-wit? He said: No. He asked : Will your masters give you his blood-wit (to pay his relatives)? He said: No. He said to the man. Take him. So he brought him out to kill him. The Messenger of Allah (ﷺ) said: If he kill him, he will be like him. This (statement) reached the man where he was listening to his statement. He said: He is here, order regarding him as you like. The Messenger of Allah (ﷺ) said: Leave him alone. And he once said: He will bear the burden of the sin of the slain and that of his own and thus he will become one of the Companions of Hell. So he let him go.