Musnad Abu Ya'la al-Mawsili 129:156

Abu Ya'la Ahmad ibn Ali ibn al-Muthanna al-Tamimi al-Mawsili informed us, Zuhayr narrated to us, Affan narrated to us, Hammad narrated to us, from Humayd, from Anas, that the Messenger of Allah (may Allah bless him and grant him peace) used to say when he entered upon a sick person: "Remove the harm, O Lord of the people, and heal, for You are the Healer. There is no healer but You. Grant a healing that leaves behind no illness." And Hammad said: "There is no healing except Your healing; grant a healing that leaves behind no illness."