Hadithcore
Sahih Muslim, 2040 g
sahih

Anas b. Malik reported:

Abu Talha saw Allah's Messenger (ﷺ) lying down upon his belly in the mosque. He came to Umm Sulaim and said: I saw Allah's Messenger (ﷺ) lying down upon the belly in the mosque, and I think he is hungry. The rest of the hadith is the same (but with the addition of these words) that Allah's messenger (ﷺ) ate (the food) and so did Abu Talha, Umm Sulaim and Anas b. Malik, but there was left some. thing which we presented to our neighbours.

وَحَدَّثَنَا الْحَسَنُ بْنُ عَلِيٍّ الْحُلْوَانِيُّ، حَدَّثَنَا وَهْبُ بْنُ جَرِيرٍ، حَدَّثَنَا أَبِي قَالَ، سَمِعْتُ جَرِيرَ بْنَ زَيْدٍ، يُحَدِّثُ عَنْ عَمْرِو بْنِ عَبْدِ اللَّهِ بْنِ أَبِي طَلْحَةَ، عَنْ أَنَسِ بْنِ مَالِكٍ، قَالَ رَأَى أَبُو طَلْحَةَ رَسُولَ اللَّهِ صلى الله عليه وسلم مُضْطَجِعًا فِي الْمَسْجِدِ يَتَقَلَّبُ ظَهْرًا لِبَطْنٍ فَأَتَى أُمَّ سُلَيْمٍ فَقَالَ إِنِّي رَأَيْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم مُضْطَجِعًا فِي الْمَسْجِدِ يَتَقَلَّبُ ظَهْرًا لِبَطْنٍ وَأَظُنُّهُ جَائِعًا ‏.‏ وَسَاقَ الْحَدِيثَ وَقَالَ فِيهِ ثُمَّ أَكَلَ رَسُولُ اللَّهِ صلى الله عليه وسلم وَأَبُو طَلْحَةَ وَأُمُّ سُلَيْمٍ وَأَنَسُ بْنُ مَالِكٍ وَفَضَلَتْ فَضْلَةٌ فَأَهْدَيْنَاهُ لِجِيرَانِنَا ‏.‏

References2 variants
In-Book Reference
Book 36, Hadith 196
USC-MSA web (English) reference
Book 23, Hadith 5064 (deprecated numbering scheme)