Musannaf Ibn Abi Shaybah 30947 — Heretics (zanadiqah): what

Suwayd bin Ghaflah reports that Sayyiduna Ali (may Allah be pleased with him) burned heretics in the marketplace. When he cast the fire upon them, he said: "Allah and His Messenger (peace and blessings be upon him) spoke the truth." Then he went back. The narrator says: I followed behind him, and he turned to me and asked: "Is it Suwayd?" I said: "Yes, O Commander of the Believers. I heard you saying something." He said: "O Suwayd, I am among ignorant people. So when you hear me say: 'The Messenger of Allah (peace and blessings be upon him) said,' then it is the truth."