Musannaf Ibn Abi Shayba 27:399

Abu Usama narrated to us, he said: Isma'il narrated to us, Qays informed us, he said: Abu Sahl, the freed slave of Uthman, informed us, he said: The Messenger of Allah (may Allah bless him and grant him peace) said during his illness: "I wish I had some of my companions with me." Aisha said: "Shall I call Abu Bakr for you?" She said: "He remained silent, so I knew that he did not want him." I said: "Shall I call Umar for you?" He remained silent, so I knew that he did not want him. I said: "Shall I call Ali for you?" He remained silent, so I knew that he did not want him. I said: "Shall I call Uthman ibn Affan for you?" He said: "Yes." So I called him. When he came, the Prophet (may Allah bless him and grant him peace) signaled to me to move away. He came and sat next to the Prophet (may Allah bless him and grant him peace), and the Messenger of Allah (may Allah bless him and grant him peace) began speaking to him, while Uthman’s color was changing. Qays said: Abu Sahl informed me, he said: When it was the Day of the House (the day of the siege), it was said to Uthman: "Will you not fight?" He said: "Indeed, the Messenger of Allah (may Allah bless him and grant him peace) entrusted a covenant to me, and I am patient upon it." Abu Sahl said: They believe that it was that (same) meeting.