Musnad Ahmad 850:14

Husayn narrated to us, al-Mubarak narrated to us, from al-Hasan, Abd al-Rahman ibn Samurah al-Qurashi narrated to us, while we were in Kabul, he said: The Messenger of Allah, peace and blessings of Allah be upon him, said to me: "O Abd al-Rahman, do not ask for leadership," and he mentioned the hadith. Harun ibn Ma'ruf narrated to us, Abdullah said: And I heard it myself from Harun ibn Ma'ruf, Damrah narrated to us, Abdullah ibn Shawdhab narrated to us, from Abdullah ibn al-Qasim, from Kathir, the freed slave of Abd al-Rahman ibn Samurah, from Abd al-Rahman ibn Samurah, he said: Uthman ibn Affan came to the Prophet, peace and blessings of Allah be upon him, with a thousand dinars in his garment, when the Prophet, peace and blessings of Allah be upon him, was equipping the Army of Hardship. He said: So he poured them into the lap of the Prophet, peace and blessings of Allah be upon him. The Prophet, peace and blessings of Allah be upon him, began turning them over with his hand and saying: "Nothing will harm Ibn Affan after today for what he does," repeating it several times.