وَإِنْ صَحَّ الْمَرِيضُ، أَوْ أَقَامَ الْمُسَافِرُ، ثُمَّ مَاتَا: لَزِمَهُمَا الْقَضَاءُ بِقَدْرِ الصِّحَّةِ، وَالْإِقَامَةِ.
Translation: If the ill person recovers or the traveller becomes resident and they subsequently die, make-up is chargeable in proportion to the time of health or residence.
The second clause addresses a person who recovered from illness or finished travelling, then died. Some days were available for making up fasts. Accordingly, the liability is proportional to that period of health or residence.
The words “to the extent of health and residence” establish the cap. This is a different case from uninterrupted illness or travel until death.