Sahih Muslim Book 26, Hadith Number 5440.

Chapter : Curing of the patient with the recitation of Mu’awwidhatan (Suras CXIII., CXIV).

‘Aisha reported that when Allah’s Messenger (may peace be upon him) fell ill, he recited over his body Mu’awwidhatan and blew over him and when his sickness was aggravated I used to recite over him and rub him with his band with the hope that it was more blessed.