Bismillah Walhamdulillah Was Salaatu Was Salaam ‘ala Rasulillah
Narrated ‘Aisha (Radi-Allahu ‘anha):
Whenever Allah’s Apostle (Sallallahu ‘Alaihi Wa Sallam) became sick, he would recite Mu’awwidhat (Surat Al-Falaq and Surat An-Nas) and then blow his breath over his body. When he became seriously ill, I used to recite (these two Suras) and rub his hands over his body hoping for its blessings.
Bukhari Vol. 6 : No. 535