Sahih Muslim 2819
Sahih Muslim · Book 52: Characteristics of the Day of Judgment, Paradise, and Hell · Doing A Lot Of Good Deeds And Striving Hard In Worship
This hadith has been transmitted on the authority of Mughira b. Shu'ba and the words are:
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ ، وَابْنُ، نُمَيْرٍ قَالاَ حَدَّثَنَا سُفْيَانُ ، عَنْ زِيَادِ بْنِ عِلاَقَةَ ، سَمِعَ الْمُغِيرَةَ بْنَ شُعْبَةَ ، يَقُولُ قَامَ النَّبِيُّ صلى الله عليه وسلم حَتَّى وَرِمَتْ قَدَمَاهُ قَالُوا قَدْ غَفَرَ اللَّهُ لَكَ مَا تَقَدَّمَ مِنْ ذَنْبِكَ وَمَا تَأَخَّرَ . قَالَ " أَفَلاَ أَكُونُ عَبْدًا شَكُورًا " .
Allah's Apostle (ﷺ) kept standing in prayer (for such long hours) that his feet were swollen. They (his Companions) said: Verily, Allah has pardoned for thee the earlier and the later of thine sins. Thereupon he said: Should I not prove myself to be a grateful servant (of Allah)?