Ibn `Abbas (Radhiallahu anhu) reported:
The Prophet (Sallallaahu ‘alaihi wasallam) said, “He who visits a sick person who is not on the point of death and supplicates seven times:
As’alullahal-`Azima Rabbal-`Arshil-`Azimi, an yashfiyaka
(I beseech Allah the Great, the Rubb of the Great Throne, to heal you),
Allah will certainly heal him from that sickness.”
[Abu Dawud and At-Tirmidhi]
There is always a great certainty that Allah will respond to a supplication which springs from a sincere, veracious heart. One should, therefore, pray for a patient with full conviction and reassurance of heart. Moreover, the Prophet’s prayers have special effect and grace and therefore their original wordings should be uttered.
Riyad-us-Saliheen – Hadith No : 906