Sunan Ibn Majah
4237
Sahih+2

It was narrated that Umm Salamah said:“By the One Who took his (ﷺ) 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.”

SahihAl-Albani
SahihMuhammad Fouad Abd al-Baqi