Musnad Ahmad 1155:28

'Abd al-Malik ibn 'Amr narrated to us, Sufyan narrated to us, from Muhammad ibn al-Munkadir, from Abu Bakr ibn Sulayman ibn Abi Hathmah, from Hafsah, that a woman from Quraysh, who was called al-Shifa', used to perform ruqyah (incantation) for the namlah (a type of skin ailment/ulcer). The Prophet, peace and blessings of Allah be upon him, said to her: "Teach it to Hafsah."