Sunan Abu Dawood, Chapter: Purification (Kitab Al-Taharah)

Abdullah ibn Salamah said: I, accompanied by other two persons, one from us and the other from Banu Asad, called upon Ali. He sent them to a certain territory (on some mission) saying: You are sturdy and vigorous people; hence display your power for religion. He then stood and entered the toilet. He then came out and called for water and took a handful of it. Then he wiped (his hands) with it and began to recite the Qur'an. They were surprised at this (action). Thereupon he said: The Apostle of Allah (peace_be_upon_him) came out from the privy and taught us the Qur'an and took meat with us. Nothing prevented him; or the narrator said: Nothing prevented him from (reciting) the Qur'an except sexual defilement.