ExpressionMeaning / point
أَحَبُّmore/most beloved; comparative form
الْأَعْمَالِdeeds; plural of عَمَل
أَدْوَمُهَاthe more consistent of them
وَإِنْ قَلَّeven if it is little
أَحَبُّ الْأَعْمَالِ raises the question of what sort of deed is most beloved, and أَدْوَمُهَا supplies the answer. وَإِنْ قَلَّ rejects the assumption that a worthwhile deed must be large in quantity.
Consistency does not mean doing the activity every moment; it means maintaining a sustainable practice at suitable intervals.