The Prophet ﷺ showed gratitude praying the night until his feet swelled
The Messenger of Allah ﷺ used to stand up after performing prayer until his feet were swollen. ʿĀʾishah said, "O Messenger of Allah, do you do this while your past and future sins have been forgiven?" He replied, "O ʿĀʾishah, should I not be a grateful servant?"
كَانَ رَسُولُ اللَّهِ ﷺ إِذَا صَلَّى قَامَ حَتَّى تَفَطَّرَ رِجْلاَهُ قَالَتْ عَائِشَةُ: يَا رَسُولَ اللَّهِ أَتَصْنَعُ هَذَا وَقَدْ غُفِرَ لَكَ مَا تَقَدَّمَ مِنْ ذَنْبِكَ وَمَا تَأَخَّرَ؟ فَقَالَ: «يَا عَائِشَةُ أَفَلاَ أَكُونُ عَبْدًا شَكُورًا؟»