Musnad Ahmad 942:2

Muhammad ibn Ja‘far narrated to us, Shu‘bah narrated to us, from ‘Abdullah ibn Abi al-Safar, from al-Sha‘bi, from Kharijah ibn al-Salt, from his paternal uncle, who said: We came from the Prophet, may Allah bless him and grant him peace, and we came upon a tribe of the Arabs. They said: "We have been informed that you have come from this man with good, so do you have a medicine or a ruqyah (incantation)? For we have a madman in chains." He said: So we said: "Yes." He said: So they brought the madman in chains. He said: So I recited the Opening of the Book (al-Fatihah) for three days, morning and evening. I would gather my saliva, then spit. He said: It was as if he were released from a tether. He said: So they gave me a payment. I said: "No, until I ask the Prophet, may Allah bless him and grant him peace." So I asked him, and he said: "Eat, for by my life, whoever eats by a false ruqyah has eaten falsehood; you have eaten by a true ruqyah."