Musnad Abu Ya'la al-Mawsili 3:275

Al-Qawariri narrated to us, Ghundar narrated to us, Shu'bah narrated to us, he said: I heard Malik ibn 'Urfutah, he said: I heard 'Abd Khayr say: I saw 'Ali rinse his mouth three times along with inhaling water [into the nose] using one handful of water. Then he said: Whoever wishes to look at the purification of the Messenger of Allah, may Allah bless him and grant him peace, then this is the purification of the Messenger of Allah, may Allah bless him and grant him peace.