The Prophet ﷺ used to offer night prayers till his feet became swollen. Somebody said, to him," "Allah has forgiven you, your faults of the past and those to follow." On that, he said, "Shouldn't I be a thankful slave of Allah)?" (Using translation from Bukhārī 4836)
صَلَّى النَّبِيُّ ﷺ حَتَّى تَوَرَّمَتْ قَدَمَاهُ فَقِيلَ لَهُ أَلَيْسَ قَدْ غُفِرَ لَكَ مَا تَقَدَّمَ مِنْ ذَنْبِكَ وَمَا تَأَخَّرَ؟ قَالَ «أَفَلَا أَكُونَ عَبْدًا شَكُورًا»