Sunan Ibn Majah, Volume 5, Book 37, Hadith 4237 (DarusSalam) ⓘ
It was narrated that Umm Salamah said: “By the One Who took his soul, he did not die until most of his prayers were offered sitting down. And the most beloved of deeds to him was a righteous deed which a person persists in doing, even if it is something small.”
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 .
also referenced under: Hadith 4237 (Reference) & Book 37, Hadith 4378 (In-Book)