Another chain:
Imam Aḥmad (1) said: Abū Nuʿaym narrated to us, and al-Walīd ibn al-Qāsim al-Hamdānī (2) likewise narrated to us; they said: Isrāʾīl related to us, from Ibrāhīm ibn ʿAbd al-Aʿlā, from Ṭāriq ibn Ziyād, who said:
ʿAlī marched to al-Nahrawān. Al-Walīd, in his version, adds: We went out with him and he killed (3) the Khārijites. Then he said, “Search for the maimed man, for the Messenger of Allah ﷺ said:
‘A people will appear who utter a word of truth, yet it will not pass beyond their throats. They will dart out of Islam just as an arrow darts through its prey. Their distinguishing mark—or among them—will be a black man whose hand is maimed, upon which are a few black hairs. If he is among them you have slain the worst of mankind, but if he is not among them you have slain the best of mankind.’”
Al-Walīd continues: We wept. [Then] we found the maimed man, so we fell in prostration, and ʿAlī also prostrated with us. Aḥmad alone transmitted this chain.
Another chain:
It was narrated by ʿAbd Allah ibn Shaddād from ʿAlī, as has just been cited in full (4).
Another chain from ʿAlī:
Muslim (5) said: Abū al-Ṭāhir and Yūnus ibn ʿAbd al-Aʿlā narrated to me; they said: ʿAbd Allah ibn Wahb informed us, ʿAmr ibn al-Ḥārith informed me, from Bukayr ibn al-Ashajj, from Busr ibn Saʿīd, from ʿUbayd Allah ibn Abī Rāfiʿ, the freedman of the Messenger of Allah:
When the Ḥarūriyya rebelled while he was with ʿAlī ibn Abī Ṭālib, they cried, “No judgment but that of Allah!” ʿAlī replied, “A word of truth by which falsehood is intended. The Messenger of Allah ﷺ described a people whose description I recognize in these: ‘They speak the truth with their tongues, yet it does not go beyond this’—and he pointed to his throat—‘They are the most hated of Allah’s creation. Among them is a black man; one of his hands is like the teat (6) of a sheep or the nipple of a breast.’”
When ʿAlī ibn Abī Ṭālib had slain them he said, “Search for him.” They looked but found nothing, so he said, “Go back and look—by Allah, I have neither lied nor been lied to,” repeating this two or three times. They then found him (7) in a ruined building, brought him to ʿAlī, and set him before him.
ʿUbayd Allah said: I was present at that incident and at ʿAlī’s statement about them.
Yūnus adds in his version: Bukayr said: A man related to me from Ibn Ḥunayn that he said, “I saw that black man.” Muslim alone recorded this version.