What is the evidence from the Sunnah regarding verses of healing (ayat ash-shifa) and sorcery (sihr), and what is the legal (shar'i) evidence for reciting over water and then bathing with it?

The texts of the Qur’an and Sunnah indicate that the Qur’an is a cure for all diseases, as Allah Almighty says: “O mankind, there has come to you an admonition from your Lord and a healing for what is in the breasts,” and His saying: “And We send down from the Qur’an that which is a healing and a mercy for the believers.” This is supported by the hadith of Abu Sa’id al-Khudri concerning ruqyah with al-Fatihah, and the hadith of Aisha regarding the Prophet’s (peace be upon him) request for the treatment of a sick person with the Book of Allah.