Is it permissible to wipe over the khuffayn for an extended period due to the hardship of washing the feet during ablution because of old age and a back illness?

The duration of wiping over the khuffayn is one day and one night for a resident, and three days and nights for a traveler. The period begins from the first wipe after nullifying ablution. If the period expires, this does not invalidate the ablution, and it is permissible to pray with this purification until one nullifies it again. The difficulty of washing the feet due to illness can be overcome by sitting or pouring water without bending down, as rubbing is not obligatory according to the majority of scholars.