Sahih Muslim | Book 26 | Chapter 22

Narrated by Uthman b. Abu al-'As Al-Thaqafi
Uthman b. Abu al-'As Al-Thaqafi reported that he made a complaint of pain to Allah's Messenger (may peace be upon him) that he felt in his body at the time he had become Muslim. Thereupon Allah's Messenger (may peace be upon him) said: Place your hand at the place where you feel pain in your body and say Bismillah (in the name of Allah) three times and seven times A'udhu billahi wa qudratihi min sharri ma ajidu wa ukhdhiru (I seek refuge with Allah and with His Power from the evil that I find and that I fear).