Mughira bin Shu'bah reported that Allah's Apostle ( صلی اللہ علیہ وسلم ) worshipped so much that his feet were swollen. It was said to him: (Why do you undergo so much hardship despite the fact that Allah has pardoned for you your earlier and later sins? Thereupon he said: May I not (prove myself) to be a grateful servant (of Allah)?