Amir bin Sa'd reported on the authority of his father that Allah's Messenger ( صلی اللہ علیہ وسلم ) said: The greatest sinner amongst the Muslims is one who asked about a thing (from Allah's Apostle) ( صلی اللہ علیہ وسلم ) which had not been forbidden for the Muslims and it was forbidden for them because of his persistently asking about it.