Musannaf Ibn Abi Shayba 21:441

Abu Khalid al-Ahmar narrated to us, from Hajjaj, from Riyah ibn Ubaydah, the freed slave of Abu Sa'id, from Abu Sa'id, who said: When the Messenger of Allah (peace and blessings of Allah be upon him) ate food, he would say: "Praise be to Allah who fed us, gave us drink, and made us Muslims."