Musnad Abu Ya'la al-Mawsili 3:146

Ubayd Allah ibn Umar narrated to us, Ghundar 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 us on a mission and said, "You two are strong men, so struggle for your religion." Then he entered the privy and relieved himself. Then he came out and took a handful of water and wiped himself with it, then he began to recite the Quran. He said: It is as if he saw that we disapproved of that, so he said, "The Messenger of Allah (peace be upon him) used to relieve himself, then come out and recite the Quran and eat meat with us. Nothing would prevent him from reciting the Quran except for Janabah (major ritual impurity)."