Abu Sa'id Uqaysa' narrates: I heard Sayyiduna Ammar (may Allah be pleased with him) say, at the time when we were heading for Siffin: The Prophet (peace and blessings be upon him) has commanded me to fight the "Nakithin" (the covenant-breakers), the "Qasitin" (those who deviate from justice) and the "Mariqin" (those who go out of the religion).
Al-Tabarani recorded it, and the narrator Abu Sa'id is matruk (abandoned).
Abu Ya'la recorded it with a da'if (weak) chain.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الفتن - أعاذنا الله منها / 12045