was the last thing to be prohibited in the Quran, and it is money taken with the mutual consent of the parties to a transaction. If someone who does not desist from it is at war with Allah and His Messenger, what, then, of someone who does not desist from other forbidden matters whose prohibition came earlier and is more severe? Hadiths from the Prophet, may Allah bless him and grant him peace, concerning fighting the Khawārij have been widely transmitted; hadith scholars regard them as mass-transmitted.

Imam Ahmad said, “The hadith concerning the Khawārij has been authentically transmitted through ten routes.” Muslim recorded them in his Sahīh, while al-Bukhārī recorded three of them: the reports of ‘Alī, Abū Sa‘īd al-Khudrī, and Sahl ibn Hunayf. The Sunan and Musnad collections contain numerous additional routes of transmission. Describing them, the Prophet, may Allah bless him and grant him peace, said:

“Any one of you would consider his prayer insignificant beside theirs, his fasting beside theirs, and his recitation beside theirs. They recite the Quran, but it does not pass beyond their throats. They pass out of Islam as an arrow passes through its quarry. Wherever you encounter them, kill them, for whoever kills them will have a reward with Allah on the Day of Resurrection. If I were to live to encounter them, I would surely kill them as ‘Ād were killed.”

The Commander of the Faithful, ‘Alī ibn Abī Tālib, fought them together with the Companions who were with him. The early generations of the Muslim community and its imams agreed that they should be fought. They did not dispute fighting them as they disputed fighting at the Battle of the Camel and at Siffīn.

During the fighting of the civil strife, the Companions fell into three groups: those who fought alongside ‘Alī, may Allah be pleased with him; those who fought alongside his opponents; and those who abstained from fighting and fought neither side. As for the Khawārij,