It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) passed by a heap of grain in the market of Madinah. He liked it, so he put his hand into it and found something inside that was not apparent on the surface (of the heap). The Prophet (peace and blessings be upon him) expressed disapproval and then said to the grain seller: "There is no deception among Muslims. Whoever deceives us is not from us."