Sahih Bukhari Volume 7, Book 71, Hadith Number 633.
Narrated By Ibn ‘Abbas : Some of the companions of the Prophet passed by some people staying at a place where there was water, and one of those people had been stung by a scorpion. A man from those staying near the water, came and said to the companions of the Prophet, “Is there anyone among you who can do Ruqya as near the water there is a person who has been stung by a scorpion.” So one of the Prophet’s companions went to him and recited Surat-al-Fatiha for a sheep as his fees. The patient got cured and the man brought the sheep to his companions who disliked that and said, “You have taken wages for reciting Allah’s Book.” When they arrived at Medina, they said, ‘ O Allah’s Apostle! (This person) has taken wages for reciting Allah’s Book” On that Allah’s Apostle said, “You are most entitled to take wages for doing a Ruqya with Allah’s Book.”