Sahih Muslim Book 26, Hadith Number 5456.

Chapter : The excellence of curing (with the help of incantation) the influence of the evil eye and small pustules and the poison (especially of snake and scorpion).

Jabir reported Allah’s Messenger (may peace be upon him) prohibited incantation. Then the people of Amr b. Hazm came to Allah’s Messenger (may peace be upon him) and said: We know an incantation which we use for curing the sting of the scorpion but you have prohibited it. They recited (the words of incantation) before him, whereupon he said: I do not see any harm (in it), so he who amongst you is competent to do good to his brother should do that.