kill them, for those who kill them will have a reward with Allah on the Day of Resurrection. If I live to encounter them, I will surely kill them as ʿĀd were killed.”

The early generations and the leading scholars agreed that these people must be fought. The first to fight them was the Commander of the Faithful, ʿAlī ibn Abī Tālib—may Allah be pleased with him. The Muslims continued fighting them during the early Umayyad and Abbasid caliphates alongside the rulers, even when those rulers were unjust. Al-Hajjāj and his deputies were among those who fought them. All the leading Muslim scholars therefore enjoin fighting them.

The Tatars and those like them depart further from the law of Islam than those who withheld zakah and the Kharijites among the people of Tā’if who refused to abandon usury. Whoever doubts that they must be fought is among the most ignorant of the religion of Islam. Whenever fighting them is obligatory, they are to be fought even if some among them are acting under compulsion, by agreement of the Muslims.

When al-ʿAbbās was captured on the day of Badr, he said:

“O Messenger of Allah, I went out under compulsion.”

The Prophet—may Allah bless him and grant him peace—replied:

“Outwardly, you were against us; as for what was within you, that rests with Allah.”

The scholars have agreed that if an army of unbelievers uses Muslim prisoners in its custody as shields, and harm to the Muslims is feared if that army is not fought, then it is to be fought, even if this leads to the killing of the Muslims used as shields. But if