حَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، وَبِشْرُ بْنُ مُعَاذٍ، قَالا‏:‏ حَدَّثَنَا أَبُو عَوَانَةَ، عَنْ زِيَادِ بْنِ عِلاقَةَ، عَنِ الْمُغِيرَةِ بْنِ شُعْبَةَ، قَالَ‏:‏ صَلَّى رَسُولُ اللهِ صلى الله عليه وسلم، حَتَّى انْتَفَخَتْ قَدَمَاهُ، فَقِيلَ لَهُ‏:‏ أَتَتَكَلَّفُ هَذَا، وَقَدْ غَفَرَ اللَّهُ لَكَ مَا تَقَدَّمَ مِنْ ذَنْبِكَ وَمَا تَأَخَّرَ‏؟‏ قَالَ‏:‏ أَفَلا أَكُونُ عَبْدًا شَكُورًا‏.‏

Abu Huraira said (may Allah be well pleased with him)

"Allah’s Messenger (Allah bless him and give him peace) used to perform the ritual prayer until his feet had begun to swell, so he was asked: 'Must you do this, when it has come to you that Allah has already forgiven you your former and your latter sins?’ He replied: 'Shall I not be a thankful servant?'”