عَن عُمَرَ بنِ الخَطَّاب رَضِيَ اللهُ عَنهُ قَالَ قَالَ رَسُولُ اللهِ صَلَّى اللهُ عَلَيهِ وَسَلَّمَ : إِذَا دَخَلتَ عَلَى مَرِيضٍ فَمُرْهُ يَدْعَو لَكَ فَإِنَّ دُعَاءَهُ كَدُعَاءِ الْمَلَائِكَةِ . (ابن ماجه ص104)
Hadhrat Umar (Radhiallahu Anhu) reports that Rasulullah (Sallallahu Alaihi Wasallam) said: “When you go to visit a sick person, then ask him to make duaa for you, for indeed his duaa is similar to the duaa of the angels (due to him being cleansed of his sins).