إِذَا دَخَلْتُمْ عَلَى الْمَرِيضِ، فَنَفِّسُوا لَهُ فِي أَجَلِهِ؛ فَإِنَّ ذَلِكَ لَا يَرُدُّ شَيْئًا وَيُطَيِّبُ بِنَفْسِهِ
Translation: When you visit a sick person, offer hopeful words about their life; this does not reverse anything decreed, but it comforts their heart.
Source: الترمذي
الْمَرِيضِ means “the patient,” فَنَفِّسُوا لَهُ “offer reassuring hope,” فِي أَجَلِهِ concerns the person’s lifespan, and يُطَيِّبُ بِنَفْسِهِ means “it comforts their spirit.”
A visit to the sick calls for gentle words and realistic encouragement. Neither alarming the patient nor making a guarantee about recovery that one cannot know is appropriate. The narration explicitly says reassuring speech does not reverse decree; it does give comfort.