الباطن
هو اسمٌ من أسماء الله الحسنى، يدل على صفة (الباطنيَّةِ)؛ أي إنه...
"It is burning the skin with a heated instrument for therapeutic purposes
"Kayy" (cauterization) is a known type of treatment for many illnesses, which could benefit a person with Allah"s permission. A piece of iron or the like is heated and then applied somewhere on the body, asking for healing from Allah. The process should only be undertaken by an expert.
"Kayy": burning the skin with a heated piece of iron or the like. "Mikwah": the tool used for cauterization.