What is the ruling on writing a Quranic verse on the body for a specific purpose and entering the toilet with it?

There is no objection to writing Quranic verses on the body for Ruqyah (definition) (exorcism/healing) and treatment. The basic principle in Ruqyah is permissibility, and there is no harm in incantations as long as they do not involve shirk (definition) (polytheism). Some imams, like Ibn Taymiyyah, have approved this method based on experience, provided that it is not done with blood or in places disrespectful to the Quran (such as the front, back, armpits, soles of the feet, or the back when lying on it). It is also necessary to ensure the cleanliness of the area when washing and to avoid its presence during a state of janabah (definition) (major ritual impurity). As for entering the restroom with it, there is no harm if it is covered by clothing.