It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that there was a man from the Quraysh whom people used to deceive in business transactions. He mentioned this matter to the Prophet (peace and blessings be upon him). The Prophet (peace and blessings be upon him) said: "Whenever you make a sale with someone, say to him: 'There is no deception in this sale.'"