Bilal bin Yahya said: When Sayyiduna Uthman (may Allah be pleased with him) was killed, a man came to Sayyiduna Hudhayfah (may Allah be pleased with him) and said to him: O Abu Abdullah, this man has been killed, and people differ about it. Sayyiduna Hudhayfah (may Allah be pleased with him) said: Prop me up! So a man propped him up against his chest, and Sayyiduna Hudhayfah (may Allah be pleased with him) said: I heard the Prophet (peace and blessings be upon him) say: "Abu al-Yaqzan is upon the fitrah (natural disposition); he will not abandon it until he dies, unless old age overtakes him, in which case the matter is different."
Al-Bazzar recorded it, and al-Tabarani recorded it in al-Mu'jam al-Awsat in abridged form; the narrators of both narrations are thiqat (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب المناقب / 15605