Musnad Ahmad 5:277

Muhammad ibn Ja‘far narrated to us, Shu‘bah narrated to us, from ‘Amr ibn Murrah, from ‘Abdullah ibn Salamah, who said: I entered upon ‘Ali ibn Abi Talib along with two men: a man from my people and a man from Banu Asad—I believe. He sent them on a mission and said, "Verily, you two are strong men, so strive for your religion." Then he entered the lavatory and relieved himself. Then he came out and took a handful of water and wiped himself with it. Then he began to recite the Qur’an. He said: It was as if he saw that we disapproved of that. Then he said, "The Messenger of Allah (peace and blessings of Allah be upon him) used to relieve himself, then come out and recite the Qur’an, and eat meat with us. Nothing would prevent him from the Qur’an except for major ritual impurity (janabah)."