the Book of Allah, opposes the Sunnah of the Messenger of Allah, may Allah bless him and grant him peace, and parts company with the Muslim community. The devil of the Khawārij was held in check while the Muslims were united during the reigns of the three caliphs, Abū Bakr, Umar and Uthmān. When the community became divided during the caliphate of Alī, may Allah be pleased with him, the devil of the Khawārij found an opportunity for rebellion. They rebelled and declared Alī, Mu'āwiyah and their supporters disbelievers. They were fought by Alī ibn Abī Tālib, whose party was the closer of the two to the truth, as is authentically reported from the Prophet, may Allah bless him and grant him peace:

“A renegade faction will emerge at a time of division among the people. The one of the two parties closer to the truth will kill them.”

Thus, when people such as Ibn Abbās, Umar ibn Abd al-Azīz and others debated them, they demonstrated the falsity of their position through the Book and the Balance. Ibn Abbās did so when they objected to Alī ibn Abī Tālib fighting his opponents at the Battle of the Camel while forbidding the pursuit of those who fled, the killing of their wounded, and the taking of their property and children as spoils. The Khawārij argued that the Book of Allah recognizes only believers and disbelievers: if those people were believers, fighting them was unlawful; and if they were disbelievers, their blood, property and children were lawful spoils.

Ibn Abbās answered them by pointing out that the Quran establishes that Ā'ishah is the Mother of the Believers. He explained that sexual relations with the Mothers of the Believers are forbidden: whoever denies that she is their mother contradicts the Book of Allah, and whoever considers sexual relations with his mother lawful contradicts the Book of Allah.

Their error lay in supposing that fighting a believer could never be lawful under any circumstances. This is also what led astray those of the Shia who went astray, for they supposed that anyone who fought Alī was a disbeliever;