Abdullah b. Dinar narrated that he heard Ibn 'Umar (Allah be pleased with them) saying:
A man mentioned to the Messenger of Allah ( صلی اللہ علیہ وسلم ) that he was deceived in a business transaction, whereupon Allah's Messenger ( صلی اللہ علیہ وسلم ) said: When you enter into a transaction, say: There should be no attempt to deceive.