Musannaf Ibn Abi Shayba 27:457

Abdullah ibn Numayr narrated to us, he said: Al-A’mash informed us, from ‘Amr ibn Murrah, from ‘Abd al-Rahman ibn Abi Layla, who said: The people’s statements regarding ‘Ali were mentioned in his presence. He said: "We sat with him, we ate with him, we drank with him, and we stood for him in matters of authority, yet I never heard him say anything of what they say." "It is sufficient for you to say: The cousin of the Messenger of Allah (may Allah bless him and grant him peace), his son-in-law, he witnessed the Pledge of Ridwan, and he witnessed Badr."