Musnad Abu Ya'la al-Mawsili 3:252

Ibrahim ibn Sa'id narrated to us, Abu Ahmad al-Zubayri narrated to us, from Isra'il, from 'Abd al-A'la, from Muhammad ibn 'Ali, from 'Ali, who said: The Messenger of Allah (peace and blessings of Allah be upon him) used to eat tharid and drink milk, and he would pray without performing ablution.