It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that a man told the Messenger of Allah (peace and blessings be upon him) that people deceive him in buying and selling. The Messenger of Allah (peace and blessings be upon him) said: "When you buy and sell, say: 'There is no deception.'" So whenever that man made a transaction, he used to say: "There is no deception."