He rolled up his sleeves, unsheathed his sword, and shook it until his hand trembled. He then said: “O Prophet of Allah! How can I kill a man who is prostrating and testifies that none has the right to be worshipped but Allah, and that Muhammad is His servant and Messenger?” The Prophet, peace and blessings be upon him, then repeated the foregoing words.

I say: This is an authentic chain of transmission according to the conditions of Muslim. Al-Haythami said (6/225): “Ahmad and al-Tabarani narrated it, without a satisfactory clarification, and Ahmad’s narrators are the narrators of the authentic collections.” In al-Isabah (2/174–175), al-Hafiz attributed it to Muhammad ibn Qudamah and al-Hakim in al-Mustadrak. I did not find it there in this wording; rather, in 2/146 he recorded, through two other chains from al-Shahham with his chain of transmission, another hadith concerning the Khawarij, which he authenticated according to the conditions of Muslim.

The hadith also has a supporting report from Anas with similar wording. It states that the first man who stood to kill him was Abu Bakr, and the second was Umar. It adds: “The Messenger of Allah, peace and blessings be upon him, said: ‘Which of you will go to this man and kill him?’ Ali said: ‘I will.’ The Messenger of Allah, peace and blessings be upon him, said: ‘It is for you to do so, if you find him.’ Ali went, but did not find him. When he returned, the Messenger of Allah, peace and blessings be upon him, asked: ‘Did you kill the man?’ He replied: ‘I did not know which way he had gone upon the earth.’ The Messenger of Allah, peace and blessings be upon him, then said: ‘This is the first faction to emerge from my Ummah. Had you killed him, no two members of my Ummah would have differed.’”

Abu Yaʿla recorded it (3/1019–1020) through Yazid al-Raqashi, who said: Anas ibn Malik narrated it to me. I say: Its narrators are those of Muslim, except al-Raqashi, who is weak. Musa ibn ʿUbaydah corroborated him: Hud ibn ʿAta’ informed me from Anas with similar wording. It includes that Abu Bakr said: “I disliked killing him while he was praying, for I had been forbidden to strike those who pray.” Abu Yaʿla recorded it (3/1025–1026). I say: Musa ibn ʿUbaydah is weak. It has a third route, narrated by ʿAbd al-Rahman ibn Sharik: My father narrated to us from al-Aʿmash, from Abu Sufyan.