In the narration of Aban ibn Uthman, it is reported that Umar ibn Al-Khattab was presented with a man who had killed another man's brother. Umar handed him over to the victim's brother and ordered him to kill him. The man struck him until he thought he had killed him. He was carried to his home, and they found he still had some life in him. They treated him until he recovered. When he recovered, the brother of the first murdered man seized him and said: "You are the killer of my brother, and I have the right to kill you." The man replied: "You have already killed me once." He was then brought before Umar, who ordered his execution. As he was being taken away, he cried out: "O' people, by Allah سبحانه وتعالى, he has already killed me once!" They passed by Imam Ali ibn Abi Talib عليه السلام and informed him of the situation. Imam Ali ibn Abi Talib عليه السلام said: "Do not rush to kill him until I come out to you." Imam عليه السلام entered upon Umar and said: "This is not the correct ruling in this matter." Umar asked: "Then what is it, O' Abu Al-Hasan عليه السلام?" Imam Ali ibn Abi Talib عليه السلام replied: "This man should exact retribution from the brother of the first murdered man for what he did to him, and then he can be executed for his brother." The man thought that if he took retribution, it would lead to his own death, so he pardoned him, and they both left each other in peace.