GRATITUDE OF THE PROPHET H praise and peace be upon him, H 99 "The Prophet, praise and peace be upon him, stood so long during his voluntary prayer at night that the skin of his feet would crack; whereupon Lady Ayesha, may Allah be pleased with her, said to him: 'O Messenger of Allah, praise and peace be upon him, why do you stand so long in prayer when Allah has forgiven you in the past and in the future?' He answered: 'Wouldn't I love to be a thankful worshiper!'" R 99 Bukhari and Muslim with a chain up to the Mother of Believers, Lady Ayesha who related this.
98- الرابع : عن عائشة رَضي الله عنها : أنَّ النَّبيّ صلى الله عليه وآله وسلم كَانَ يقُومُ مِنَ اللَّيلِ حَتَّى تَتَفَطَّرَ قَدَمَاهُ فَقُلْتُ لَهُ : لِمَ تَصنَعُ هَذَا يَا رسولَ الله ، وَقدْ غَفَرَ الله لَكَ مَا تَقَدَّمَ مِنْ ذَنْبِكَ وَمَا تَأَخَّرَ ؟ قَالَ : "أَفَلا أُحِبُّ أنْ أكُونَ عَبْداً شَكُوراً" مُتَّفَقٌ عَلَيهِ ، هَذَا لفظ البخاري . ونحوه في الصحيحين من رواية المغيرة بن شعبة .