Ali bin al-Madini علي بن المديني · Wages (Kitab Al-Ijarah)

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."