(34) باب الْمُؤْمِنُ يَأْكُلُ فِي مِعًى وَاحِدٍ وَالْكَافِرُ يَأْكُلُ فِي سَبْعَةِ أَمْعَاءٍ
Ibn 'Umar reported Allah's Messenger (ﷺ) as saying:
A believer eats in one intestine, whereas a non-believer eats in seven intestines.
Reference: Sahih Muslim 2061 a
In-book reference: Book 36, Hadith 249
USC-MSA web (English) reference(deprecated numbering scheme): Book 23, Hadith 5116