Musnad Ahmad 32:590

'Abd al-Samad narrated to us, my father narrated to me, 'Abd al-'Aziz narrated to us, he said: We entered upon Anas ibn Malik with Thabit. Thabit said: "I have been afflicted with an illness." He (Anas) said: "Shall I not perform *ruqyah* (incantation) upon you with the *ruqyah* of Abu al-Qasim, peace and blessings be upon him?" He said: "Yes." He said: "Say: 'O Allah, Lord of the people, Remover of the affliction, heal, for You are the Healer; there is no healer but You, a healing that leaves behind no sickness.'"