Chapter on Fighting the Rebellious Faction
Introduction
Qitāl (fighting) is the verbal noun of qātala, meaning to wage war against someone and engage him in combat.

Baghy (rebellion): the verb baghā ʿalayhi—with a voiced ghayn, baghyan, with the bāʾ pronounced with fatḥah and the ghayn silent—signifies aggression, injustice, and deviation from the truth.

Here it refers to those unjust rebels who break away from obedience to the imam and attack him. When they forsake the obedience that is due from them, the imam summons them and dispels their doubts. If they concede the matter and abandon their rebellion, he leaves them in peace. If they refuse, he admonishes them and warns them of combat; should they persist, he fights them, in keeping with the Almighty’s words: “So fight the faction that rebels until it returns to the command of Allah” (Quran 49:9).

Al-Wazīr said: “There is consensus that if a powerful group rises against the Muslim imam on the strength of a plausible interpretation, it is permissible to fight them until they return to the command of Allah.”

The installation of an imam for the Muslims is obligatory: to safeguard the stronghold of Islam, defend its frontiers, enforce the prescribed penalties, secure people’s rights, enjoin what is right, forbid what is wrong, and administer the affairs of the Muslims.

His authority is established by one of the following means:
1 – By the free choice and consensus of the Muslims, as in the caliphate of Abu Bakr al-Ṣiddīq.
2 – By explicit nomination from the previous imam, as when Abu Bakr al-Ṣiddīq, may Allah be pleased with him, appointed ʿUmar ibn al-Khaṭṭāb.