Sahih Muslim Book 26, Hadith Number 5425.
Chapter : Medicine and spell.
Abu Sa’id reported that Gabriel came to Allah’s Messenger (may peace be upon him) and said: Muhammad, have you fallen ill? Thereupon he said: Yes. He (Gabriel) said: “In the name of Allah I exercise you from everything and safeguard you from every evil that may harm you and from the eye of a jealous one. Allah would cure you and I invoke the name of Allah for you.”