Narrated Abu Hurairah:
That the Messenger of Allah (ﷺ) passed by a pile of food. He put his fingers in it and felt wetness. He said: 'O owner of the food! What is this ?' He replied: 'It was rained upon O Messenger of Allah.' He said: 'Why not put it on top of the food so the people can see it?' Then he said: 'Whoever cheats, he is not one of us.'
He said: There are narrations on this topic from Ibn 'Umar, Abu Al-Hamra', Ibn 'Abbas, Buraidah, Abu Burdah bin Niyar, and Hudhaifah bin Al-Yaman.
[Abu 'Eisa said:] The Hadith of Abu Hurairah is Hasan Sahih Hadith. This is acted upon according to the people of knowledge. They dislike cheating and they say that cheating is unlawful.