What is the ruling on using seven pieces of salt, moved over a patient's head while reciting Ayat al-Kursi and the Mu'awwidhat, then thrown into a fire with the intention of healing? And does the good intention of the healer affect the Sharia ruling on this act, knowing that a small sum of money may be requested in return?

Allah has legislated treatment with whatever has been proven beneficial by the Sharia (definition), or by experience and the science of medicine and observation, and has legislated giving a fee to the healer. Among what has been proven beneficial by the Sharia are: Zamzam water, honey, the black seed (Nigella sativa), and legal ruqyah (definition). Whatever has not been proven beneficial by the Sharia or by experience must be abandoned, as it may be from the whispers of devils, and believing in its intrinsic benefit is shirk (definition) (polytheism). As for reciting the Quran and the prescribed remembrances (adhkar), they are permissible.