and the answer is that this could be defiance synonymous with disbelief that means leaving the faith, and it could be defiance synonymous with disbelief that does not mean leaving the faith but rather what the interpreter of the Quran said, that it is disbelief less than disbelief. and this ḥadīth confirms that disbelief can have this meaning because Allāh said: "And if two groups of believers fight each other, then make peace between them. But if one of them oppresses the other, then fight against the one that oppresses until it returns to the command of Allāh" (Sūrah al-Ḥujurāt, 49:9). for our Lord mentioned here the oppressing group that fights the rightful believing group, yet He did not judge the oppressing group as disbelievers, even though the ḥadīth says: "...and fighting him is disbelief." therefore, fighting him is disbelief less than disbelief, just as Ibn ʿAbbās said in the interpretation of the previous verse. so the fighting of a Muslim against another Muslim is rebellion, aggression, defiance, and disbelief, but this means that disbelief can be practical disbelief and can be doctrinal disbelief. from here comes this precise detail that was explained and clarified by the imam—rightfully—Shaykh al-Islām Ibn Taymiyyah, and after him, his distinguished student Ibn Qayyim al-Jawziyyah, as they have the credit for highlighting and emphasizing the division of disbelief into that division which the interpreter of the Quran raised with that comprehensive and concise word. so Ibn Taymiyyah and his student and companion Ibn Qayyim al-Jawziyyah always emphasize the necessity of distinguishing between doctrinal disbelief and practical disbelief, otherwise a Muslim might unknowingly fall into the trial of leaving the community of Muslims, as the Khawārij did in the past and some of their followers do in the present. in summary, the saying of the Prophet (ṣallá Allāhu ʿalayhi wa-sallam) "...and fighting him is disbelief" does not mean—at all—leaving the faith. and there are many ḥadīths on this matter, all of which are a decisive proof against those who adhere to their limited understanding of the previous verse and insist on interpreting it as doctrinal disbelief. so this ḥadīth is sufficient for us now because it is a definitive proof that the fighting of a Muslim against his fellow Muslim is disbelief in the sense of practical disbelief, not doctrinal disbelief. so if we return to the "Group of Takfīr"—or those who branched from them—and their labeling of rulers—and those who live under their banner, especially those who are organized under their command and employment—as disbelievers and apostates, this is based on their corrupt viewpoint that these people committed sins and thus became disbelievers because of that