Survived editing on April 01, 2026

Whoever rebels against a Muslim leader is a Khawarij

Imam Al-Barbahari :

Whoever rebels against a leader (or a ruler) among the leaders of the Muslims is a Kharijite (Khawarij); he has splintered the unity of the Muslims and contradicted the prophetic narrations. His death is the death of [one in] the Days of Ignorance (Jahiliyyah).

ومن خرج على إمام من أئمة المسلمين فهو خارجي قد شق عصا المسلمين وخالف الآثار وميتته ميتة جاهلية

Source : Sharh as-Sunnah p.29 Link