for he said:

“One of you would consider his own prayer insignificant compared with theirs, his fasting compared with theirs, and his recitation compared with 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.”

Thus, fighting the Harūriyyah was established by the Sunnah of the Prophet, may Allah bless him and grant him peace, and the agreement of his Companions. Fighting them was not a battle of civil strife like the fighting that occurred between two great groups of Muslims. Rather, it is established in an authentic hadith narrated by al-Bukhārī that the Prophet, may Allah bless him and grant him peace, said to his son al-Hasan:

“This son of mine is a leader, and through him Allah will reconcile two great groups of Muslims.”

He also said in an authentic hadith:

“A renegade faction will break away at a time of division among the Muslims, and the nearer of the two groups to the truth will kill them.”

This indicates that al-Hasan’s decision to refrain from fighting was either obligatory or recommended, for the Prophet, may Allah bless him and grant him peace, would not have praised him for abandoning something obligatory or recommended. The other hadith indicates that those who fought the Khawārij—namely, ‘Alī and his companions—were nearer to the truth than Mu‘āwiyah and his companions. It also indicates that the Prophet, may Allah bless him and grant him peace, commanded fighting the Khawārij. Fighting them was not like the fighting at the Battle of the Camel and at Siffīn, for which there was no command from the Prophet.

The point is that ‘Alī ibn Abī Tālib and others among his companions did not declare them unbelievers, nor did they fight them until the Khawārij initiated hostilities against them. Scholars have differed over declaring the adherents of religious innovations and deviant inclinations unbelievers and over their remaining eternally in the Fire. “Two views” on this matter have been reported from every one of the imams