Musnad Ahmad 626:47

Isma'il narrated to us, Layth informed us, from Mujahid, from al-'Aqqar ibn al-Mughirah ibn Shu'bah, from his father, from the Prophet, peace and blessings of Allah be upon him, that he said: "Whoever cauterizes himself, or seeks Ruqyah (incantation), has become free of reliance (Tawakkul) upon Allah."