The Debate with the Khawarij

After the arbitration at Siffin, a large group broke away from 'Ali and gathered at Harura'. They declared that 'Ali had erred by accepting human arbitration, saying judgment belongs to Allah alone. 'Ali sent Ibn 'Abbas to speak with them.

According to the report, Ibn 'Abbas answered each objection from the Qur'an: that Allah Himself commands people to judge in matters such as compensation for game killed in pilgrim sanctity, and between a husband and wife, so surely it was permitted to appoint arbitrators to protect the blood of the Muslims. He asked whether they had grounds for rejecting 'Ali's character, and about their other complaints.

A large number, reported as thousands, are said to have returned afterwards. The rest were not persuaded and the conflict continued. The story shows how he used the Qur'an to win hearts rather than to condemn.