Zayd bin Wahb reported,

Salama bin Kuhayl reported that he was among the army that accompanied Ali on his march against the Khawarij. Ali addressed the people, saying, "People, I heard the Messenger of Allah ﷺ say, 'A group will emerge from my Ummah who recite the Quran in such a way that your recitation will be nothing compared to theirs, your prayer nothing compared to their prayer, and your fasting nothing compared to their fasting. They will recite the Quran thinking it is in their favor, when in fact it is against them. Their prayer will not pass beyond their collarbones. They will pass through Islam as an arrow passes through its prey. If the army that defeats them knew what has been decreed for them by the tongue of their Prophet ﷺ, they would rely on this deed alone. The sign of this is that among them is a man with an upper arm but no forearm. At the tip of his upper arm there is something resembling a nipple, with white hairs on it.' Will you then march against Muawiya and the people of Syria, leaving these people behind to take your place among your offspring and your wealth? By Allah, I truly hope these are the very people, for they have shed sacred blood and raided the people's grazing herds. So march, in the name of Allah."Salama bin Kuhayl said, Zayd bin Wahb took me through each stage of the journey until he said, "We crossed a bridge, and when the two sides met, the Khawarij that day were under the command of Abdullah bin Wahb al-Rasibi. He said to them, 'Throw down your spears and draw your swords from their sheaths, for I fear they will appeal to you as they did at the day of Harura.' So they turned back, cast aside their spears, and drew their swords. The people then thrust at them with their spears, and they were killed one upon another. Only two men from our side were struck down that day."Ali said, "Search among them for the man with the deformed arm." They searched but did not find him. Ali himself rose and went to a group of slain men piled upon one another. He said, "Move them aside." They found him beneath the others, lying against the ground. Ali pronounced the takbir and then said, "Allah has spoken the truth, and His Messenger has conveyed it."Then Ubayda al-Salmani stood and approached him, saying, "Commander of the Believers, by Allah, besides whom there is no god, did you truly hear this hadith from the Messenger of Allah ﷺ?"Ali replied, "Yes, by Allah, besides whom there is no god."He continued asking him to swear three times, and Ali swore to him each time.

عن زيد بن وهب الجهني

أنه كان في الجيش الذين كانوا مع علي الذين ساروا إلى الخوارج، فقال علي: أيها الناس إني عت رسول الله ﷺ يقول: يخرج قوم من أمتي يقرؤون القرآن ليس قراءتكم إلى قرائتهم بشيء، ولا صلاتكم إلى صلاتهم بشيء، ولا صيامكم إلى صيامهم بشيء، يقرؤون القرآن يحسبون أنه لهم وهو عليهم، لا تجاوز صلاتهم تراقيهم، يمرقون من الإسلام كما يمرق السهم من الرمية، لو يعلم الجيش الذي يصيبونهم ما قضي لهم على لسان نبيهم ﷺ لا تكلوا عن العمل، وآية ذلك أن فيهم رجلا له عضد، وليس له ذراع، على رأس عضده مثل حلمة الثدي، عليه شعرات بيض، فتذهبون إلى معاوية وأهل الشام، وتتركون هؤلاء يخلفونكم في ذراريكم وأموالكم والله إني لأرجو أن يكونوا هؤلاء القوم، فإنهم قد سفكوا الدم الحرام، وأغاروا في سرح الناس، فسيروا على اسم الله. قال سلمة بن كهيل: فنزلني زيد بن وهب منزلا حتى قال: مررنا على قنطرة، فلما التقينا وعلى الخوارج يومئذ عبد الله بن وهب الراسبي، فقال لهم: ألقوا الرماح وسلوا سيوفكم من جفونها، فإني أخاف أن يناشدوكم كما ناشدوكم يوم حروراء، فرجعوا، فوحشوا برماحهم، وسلوا السيوف، وشجرهم الناس برماحهم قال: وقتل بعضهم على بعض، وما أصيب من الناس يومئذ إلا رجلان، فقال علي: التمسوا فيهم المخدج، فالتمسوه، فلم يجدوه، فقام علي بنفسه، حتى أتى ناسا قد قتل بعضهم على بعض، قال: أخروهم فوجدوه مما يلي الأرض، فكبر، ثم قال: صدق الله، وبلغ رسوله، قال: فقام إليه عبيدة السلماني، فقال: يا أمير المؤمنين، الله الذي لا إله إلا هو لسمعت هذا الحديث من رسول الله ﷺ؟ فقال: إي والله الذي لا إله إلا هو، حتى استحلفه ثلاثا، وهو يحلف له.