Musannaf Ibn Abi Shayba 16:317

Abu Bakr narrated to us, he said: Ibn Numayr narrated to us, from Sufyan, from Abu al-Zubayr, from Jabir, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "The believer eats in one intestine, and the disbeliever eats in seven intestines."