Mu'jam Kabir Tabarani 8580 — I sat in the gathering of Sayyiduna

Amr bin Maymun said: I sat in the gathering of Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him), I think he said for a year, and during that time we did not hear him narrate a hadith from the Messenger of Allah (peace and blessings be upon him), except that one day while he was talking, it came onto his tongue: "The Messenger of Allah (peace and blessings be upon him) said," and distress overcame him until I saw the sweat dripping from him. He said: "If Allah wills, it is either a little more than this, or close to this, or a little less than this."