Sunan Ibn Majah, Hadith 2225 ⓘ
It was narrated that Abu Hamra' said: "I saw the Messenger of Allah pass by a man having food in a vessel. He put his hand in it and said: 'Perhaps you are cheating. Whoever cheats us is not one of us."'
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا أَبُو نُعَيْمٍ، حَدَّثَنَا يُونُسُ بْنُ أَبِي إِسْحَاقَ، عَنْ أَبِي دَاوُدَ، عَنْ أَبِي الْحَمْرَاءِ، قَالَ رَأَيْتُ رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ مَرَّ بِجَنَبَاتِ رَجُلٍ عِنْدَهُ طَعَامٌ فِي وِعَاءٍ فَأَدْخَلَ يَدَهُ فِيهِ فَقَالَ " لَعَلَّكَ غَشَشْتَهُ مَنْ غَشَّنَا فَلَيْسَ مِنَّا " .
also referenced under: Book 12, Hadith 2310 (In-Book) & Volume 3, Book 12, Hadith 2225 (DarusSalam)