Musnad Abu Ya'la al-Mawsili 154:3

Muhammad ibn 'Abbad al-Makki narrated to us, Sufyan narrated to us, from 'Amr, from Ibn 'Umar, that he said to a person who was a heavy eater: "Indeed, the Messenger of Allah (ﷺ) said: 'The believer eats in one intestine, and the disbeliever eats in seven intestines.'" The man said: "As for me, I believe in Allah and His Messenger."