حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا أَبُو الأَحْوَصِ، عَنْ أَبِي إِسْحَاقَ، عَنْ أَبِي سَلَمَةَ، عَنْ أُمِّ سَلَمَةَ، قَالَتْ ‏:‏ وَالَّذِي ذَهَبَ بِنَفْسِهِ ـ صلى الله عليه وسلم ـ مَا مَاتَ حَتَّى كَانَ أَكْثَرُ صَلاَتِهِ وَهُوَ جَالِسٌ وَكَانَ أَحَبَّ الأَعْمَالِ إِلَيْهِ، الْعَمَلُ الصَّالِحُ الَّذِي يَدُومُ عَلَيْهِ الْعَبْدُ وَإِنْ كَانَ يَسِيرًا ‏.‏

It wasnarrated that Umm Salamah said: “By the One Who took his (PBUH)soul, he did not die until most of his prayers were offered sittingdown. And the most beloved of deeds to him was a righteous deed whicha person persists in doing, even if it is something small.” Translation Not Available

Book Ref: Sunan Ibn Majah Book 37 Hadith 4237
Web Ref:  Sunan Ibn Majah Vol 5 Book 37 Hadith 4237