"There is no Muslim worshiper who visits one who is ill - other than at the time of death - and he says seven times: As'alullah Al-'Azeem Rabbal 'Arshil 'Azeem an yashfik ('I ask Allah the Magnificent, Lord of the Magnificent Throne to cure you') except when he will be cured."  

عَنِ النَّبِيِّ ﷺ أَنَّهُ قَالَ مَا مِنْ عَبْدٍ مُسْلِمٍ يَعُودُ مَرِيضًا لَمْ يَحْضُرْ أَجَلُهُ فَيَقُولُ سَبْعَ مَرَّاتٍ أَسْأَلُ اللَّهَ الْعَظِيمَ رَبَّ الْعَرْشِ الْعَظِيمِ أَنْ يَشْفِيَكَ إِلاَّ عُوفِيَ