Narrated Abu Hurairah:

The Messenger of Allah (ﷺ) passed a man who was selling grain. He asked him: How are you selling? He informed him. Revelation them came down to him saying: "Put your hand into it." So he put his hand into it, and felt that it was damp. The Messenger of Allah (ﷺ) then said: "He who deceives has nothing to do with us."

حَدَّثَنَا أَحْمَدُ بْنُ مُحَمَّدِ بْنِ حَنْبَلٍ، حَدَّثَنَا سُفْيَانُ بْنُ عُيَيْنَةَ، عَنِ الْعَلاَءِ، عَنْ أَبِيهِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم مَرَّ بِرَجُلٍ يَبِيعُ طَعَامًا فَسَأَلَهُ ‏"‏ كَيْفَ تَبِيعُ ‏"‏ ‏.‏ فَأَخْبَرَهُ فَأُوحِيَ إِلَيْهِ أَنْ أَدْخِلْ يَدَكَ فِيهِ فَأَدْخَلَ يَدَهُ فِيهِ فَإِذَا هُوَ مَبْلُولٌ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ لَيْسَ مِنَّا مَنْ غَشَّ ‏"‏ ‏.‏