Maliks Muwatta Book 049, Hadith Number 009.

Section : The Intestines of the Kafir.

Yahya related to me from Malik from Abu'z-Zinad from al-Araj that Abu Hurayra said, "The Messenger of Allah, may Allah bless him and grant him peace, said, 'The muslim eats in one intestine, and the kafir eats in seven!'"