Narrated Ibn 'Umar (RA): A man told Allah's Messenger ( صلی اللہ علیہ وسلم ) that he was being deceived (cheated) in business transactions, and he replied, "When you make a purchase say, 'Deceiving (cheating) is not allowed (i.e. he has the choice to return the goods if he wills).'" [Agreed upon] .