Most historiographers trace their origin to the event of Arbitration.
Yahya related to me from Malik from Yahya ibn Said that Abu Bakr as-Siddiq was sending armies to ash-Sham.
The sign by which these people will be recognized will be a man whose one hand or breast will be like the breast of a woman or like a moving piece of flesh.
Your brother, and at your service, Surkheel Abu Aaliyah Wa alaykum al-salam wa rahmatullah.
This is the basis on which the Khawarij make the blood of Muslims lawful to shed.
He 'Ali then pronounced Allahu Akbar Allah is the Greatest and then said, Allah told the Truth and His Messenger may peace be upon him conveyed it.