Anas (May Allah be pleased with him) reported:
I said to Thabit (May Allah had Mercy upon him) Should I not perform Ruqyah (i.e., recite supplication or Quranic Ayat and blow) over you, such supplication as was practised by the Messenger of Allah (ﷺ)?" He said: "Please do so." Anas (May Allah be pleased with him) supplicated: "Allahumma Rabban-nasi, mudh-hibal-ba'si, ishfi Antash-Shafi, la shafiya illa Anta, shifa'an la yughadiru saqaman [O Allah! the Rubb of mankind! Take away this disease and cure (him or her). You are the Curer. There is no cure except through You. Cure (him or her), a cure that leaves no disease]."[Al-Bukhari].
App reference: Book 7, Hadith 10
Arabic/English book reference: Book 7, Hadith 903