In this short video, Mufti Abdur-Rahman ibn Yusuf discusses the hadith that explains what to say when visiting a sick person.
The hadith is: When you go to visit the ill, express belief that he will live long, because [although] this will not avert anything, it will comfort him (Tirmidhī, Ibn Māja).
We should give these duas for the person to have a long life because these duas will comfort the person. We don’t know what will happen to this person so it is important to comfort them and make them feel better.