كتاب الأشربة
36  
The Book of Drinks
(34)
Chapter: The believer eats in one intestine and the disbeliever eats in seven intestines.
(34)
باب الْمُؤْمِنُ يَأْكُلُ فِي مِعًى وَاحِدٍ وَالْكَافِرُ يَأْكُلُ فِي سَبْعَةِ أَمْعَاءٍ ‏‏
Sahih Muslim 2063

Abu Huraira reported that Allah's Messenger (ﷺ) invited a non-Muslim. Allah's Messenger (ﷺ) commanded that a goat be milked for him. It was milked and he drank its milk. Then the second one was milked and he drank its milk, and then the other one was milked and he drank its milk. till he drank the milk of seven goats. On the next morning he embraced Islam. And Allah's Messenger (ﷺ) commanded that a goat should be milked for him and he drank its milk and then another was milked but he did not finish it, whereupon Allah's Messenger (ﷺ) said:

A believer drinks In one intestine whereas a non-believer drinks in seven intestines.
وَحَدَّثَنِي مُحَمَّدُ بْنُ رَافِعٍ، حَدَّثَنَا إِسْحَاقُ بْنُ عِيسَى، أَخْبَرَنَا مَالِكٌ، عَنْ سُهَيْلِ بْنِ، أَبِي صَالِحٍ عَنْ أَبِيهِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم ضَافَهُ ضَيْفٌ وَهُوَ كَافِرٌ فَأَمَرَ لَهُ رَسُولُ اللَّهِ صلى الله عليه وسلم بِشَاةٍ فَحُلِبَتْ فَشَرِبَ حِلاَبَهَا ثُمَّ أُخْرَى فَشَرِبَهُ ثُمَّ أُخْرَى فَشَرِبَهُ حَتَّى شَرِبَ حِلاَبَ سَبْعِ شِيَاهٍ ثُمَّ إِنَّهُ أَصْبَحَ فَأَسْلَمَ فَأَمَرَ لَهُ رَسُولُ اللَّهِ صلى الله عليه وسلم بِشَاةٍ فَشَرِبَ حِلاَبَهَا ثُمَّ أَمَرَ بِأُخْرَى فَلَمْ يَسْتَتِمَّهَا فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ "‏ الْمُؤْمِنُ يَشْرَبُ فِي مِعًى وَاحِدٍ وَالْكَافِرُ يَشْرَبُ فِي سَبْعَةِ أَمْعَاءٍ ‏"‏ ‏.‏
Reference : Sahih Muslim 2063
In-book reference : Book 36, Hadith 253
USC-MSA web (English) reference : Book 23, Hadith 5120
  (deprecated numbering scheme)