Musannaf Ibn Abi Shaybah 40534 — Reports on Uthman (may Allah be)

It is narrated from Ammarah bin Abd, who said: Sayyiduna Hudhayfah (may Allah be pleased with him) said: "Beware of the doors of rulers, for they are places of trial; except that a trial comes in a doubtful form and leaves in a clear form." (That is, when a trial breaks out, what is true and right is not clear and evident; when it has gone, a person realizes that his action was a mistake.)