Mughira b. Shu'ba reported that Allah's Apostle ﷺ 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)?

حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا أَبُو عَوَانَةَ، عَنْ زِيَادِ بْنِ عِلاَقَةَ، عَنِ الْمُغِيرَةِ بْنِ،
شُعْبَةَ أَنَّ النَّبِيَّ ﷺ صَلَّى حَتَّى انْتَفَخَتْ قَدَمَاهُ فَقِيلَ لَهُ أَتَكَلَّفُ هَذَا وَقَدْ
غَفَرَ اللَّهُ لَكَ مَا تَقَدَّمَ مِنْ ذَنْبِكَ وَمَا تَأَخَّرَ فَقَالَ
" أَفَلاَ أَكُونُ عَبْدًا شَكُورًا " .