The ruling on those who rebelled against 'Ali: The Khawarij or the rebels?

Question:
He says: Honorable Shaykh, may Allah grant you success, are those who rebelled against 'Ali (may Allah be pleased with him) considered among the Khawarij or the rebels? And what did he mean by his statement, "Our brothers rebelled against us"?

Answer:
Those who rebelled against 'Ali are the Khawarij; they are the Khawarij. Those who rebelled against 'Ali from the Haruriyyah, and those he fought at al-Nahrawan, are the Khawarij. As for those who fought him alongside Mu'awiyah from the people of Sham, they are not called rebels, nor are they called Khawarij. 'Ali said, "Our brothers rebelled against us." 'Ali held that the Khawarij are not to be declared disbelievers. We told you that there is scholarly disagreement regarding the Khawarij: some scholars declare them disbelievers, and some do not. His use of the word "rebelled" indicates that he did not view their actions as disbelief. Yes.