Shaqiq bin Salamah (may Allah have mercy on him) says: A man said: Who is there that recognises the rebels, on the day the polytheists — that is, the people of al-Nahr — were killed? Sayyiduna Ali (may Allah be pleased with him) said: They were far from shirk (polytheism). He said: Then were they hypocrites? He said: The hypocrites remember Allah only a little. He then asked: So who were they? He said: A rebellious people over whom we were granted victory.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قتال أهل البغي / 16722