Making dua for the sick when you visit them; Sickness expiates sins of a believer
BUKHARI 5662:
from Ibn ʿAbbās —
Messenger of Allah ﷺ entered upon a man for a sick visit and said to him:
"lā baʾs, ṭahūrun, in shā Allāh!"
(It's okay, ˹its spiritual˺ cleansing ˹for your faults˺, by the Will of Allah)
The man said, "No, it is in fact a fever that is boiling within an old man and will send him to his grave." On that, the Prophet ﷺ said, "Then yes, so be it."
البخاري ٥٦٦٢:
عن ابن عباس —
أَنَّ رَسُولَ اللَّهِ ﷺ دَخَلَ عَلَى رَجُلٍ يَعُودُهُ فَقَالَ:
«(لاَ بَأْسَ، طَهُورٌ، إِنْ شَاءَ اللَّهُ!)»
فَقَالَ: كَلاَّ، بَلْ حُمَّى تَفُورُ عَلَى شَيْخٍ كَبِيرٍ كَيْمَا تُزِيرَهُ الْقُبُورَ۔ قَالَ النَّبِيُّ ﷺ: «فَنَعَمْ، إِذًا۔»