Sahih Muslim 8999
In-book no 1722وَحَدَّثَنَا ابْنُ نُمَيْرٍ، حَدَّثَنَا أَبِي، حَدَّثَنَا سَعْدُ بْنُ سَعِيدٍ، أَخْبَرَنِي الْقَاسِمُ بْنُ مُحَمَّدٍ، عَنْ عَائِشَةَ، قَالَتْ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " أَحَبُّ الأَعْمَالِ إِلَى اللَّهِ تَعَالَى أَدْوَمُهَا وَإِنْ قَلَّ " . قَالَ وَكَانَتْ عَائِشَةُ إِذَا عَمِلَتِ الْعَمَلَ لَزِمَتْهُ .
'A'isha reported Allah's Messenger (ﷺ) as saying: The acts most pleasing to Allah are those which are done continuously, even if they are small. and when 'A'isha did any act she did it continuously.