Musnad Ahmad 27:1322

'Affan narrated to us, Abu 'Awanah narrated to us, 'Uthman ibn 'Abdullah ibn Mawhab narrated to us, he said: A man from Egypt came to perform Hajj to the House. He said: He saw some people sitting, so he said: "Who are these people?" They said: "Quraysh." He said: "Who is the old man among them?" They said: "'Abdullah ibn 'Umar." He said: "O Ibn 'Umar, I am going to ask you about something, and I adjure you by the sanctity of this House, do you know that 'Uthman fled on the day of Uhud?" He said: "Yes." He said: "Do you know that he was absent from Badr and did not witness it?" He said: "Yes." He said: "And do you know that he was absent from the Pledge of Ridwan?" He said: "Yes." The Egyptian shouted "Allahu Akbar." Ibn 'Umar said: "Come here, so I may clarify to you what you asked me about. As for his fleeing on the day of Uhud, I bear witness that Allah has pardoned him and forgiven him. As for his absence from Badr, he had the daughter of the Messenger of Allah (peace and blessings of Allah be upon him) as his wife, and she was ill, so the Messenger of Allah (peace and blessings of Allah be upon him) said to him: 'You have the reward of a man who witnessed Badr and his share [of the spoils].' As for his absence from the Pledge of Ridwan, if there had been anyone in the valley of Makkah more honorable than 'Uthman, he would have sent him. The Messenger of Allah (peace and blessings of Allah be upon him) sent 'Uthman, and the Pledge of Ridwan took place after 'Uthman had gone. So he struck with his [own] hand and said: 'This is for 'Uthman.'" Ibn 'Umar said: "Take this [explanation] with you now!"