Musannaf Ibn Abi Shayba 36:340

Hashim ibn al-Qasim narrated to us, he said: ‘Ikrimah ibn ‘Ammar narrated to us, he said: Iyas ibn Salamah narrated to me, he said: My father informed me, he said: My uncle challenged Marhab the Jew to a duel on the day of Khaybar. Marhab said: "Khaybar has surely known that I am Marhab, Fully armed, a tested hero, When wars approach, blazing." My uncle ‘Amir said: "Khaybar has surely known that I am ‘Amir, Fully armed, an adventurous hero." They exchanged two blows. Marhab’s sword fell upon ‘Amir’s shield, and the sword rebounded onto his own leg, severing his main artery, and his life was in that. Salamah said: I met some of the Companions of the Prophet, may Allah bless him and grant him peace, and they said: ‘Amir’s deeds have been rendered void; he killed himself. Salamah said: I came to the Prophet of Allah, may Allah bless him and grant him peace, weeping. I said: O Messenger of Allah, ‘Amir’s deeds have been rendered void. He said: "Whoever said that has lied. Rather, he has his reward twice." When he went out to Khaybar, he began to recite rajaz poetry to the Companions of the Messenger of Allah, may Allah bless him and grant him peace, and among them was the Prophet, may Allah bless him and grant him peace, driving the caravan, and he was saying: "By Allah, were it not for Allah, we would not have been guided, Nor would we have given charity, nor would we have prayed. Indeed, those who have transgressed against us, If they desire discord, we refuse. And we have not become independent of Your bounty, So make firm our feet if we meet [the enemy], And send down tranquility upon us." The Messenger of Allah, may Allah bless him and grant him peace, said: "Who is this?" He said: ‘Amir, O Messenger of Allah. He said: "May your Lord forgive you." He never asked for forgiveness for a person specifically except that he was martyred. When ‘Umar ibn al-Khattab heard that, he said: O Messenger of Allah, if only you had let us enjoy ‘Amir! Then he stood up and was martyred. Salamah said: Then the Messenger of Allah, may Allah bless him and grant him peace, sent me to ‘Ali and said: "I will surely give the banner today to a man who loves Allah and His Messenger, or whom Allah and His Messenger love." He said: So I brought him, leading him, while he had eye inflammation. He said: The Messenger of Allah, may Allah bless him and grant him peace, spat into his eyes, then gave him the banner. Marhab came out, brandishing his sword, and said: "Khaybar has surely known that I am Marhab, Fully armed, a tested hero, When wars approach, blazing." ‘Ali ibn Abi Talib, may Allah be pleased with him, said: "I am the one whom my mother named Haydarah, Like a lion of the forests, fearsome in appearance, I will repay them with the measure of the Sandarah [a large measure]." He split Marhab’s head with the sword, and the victory was at his hands, may Allah have mercy on him.