Is it permissible to exercise ijtihad (independent reasoning) in selecting verses, hadiths, and supplications for Ruqyah Shariah (Islamic exorcism/healing), or must one be restricted to what has been authentically established in sound hadiths?

It is permissible for the rāqī (healer performing ruqyah) to perform ruqyah with the entirety of the Qur’an, and with the duʿāʾ (supplications) and lawful taʿwīdhāt (invocations for protection) that are permissible, or with whatever correct and appropriate duʿāʾ Allah enables him to utter, if he does not confine himself to the specific ruqyah that has been transmitted. Scholars have unanimously agreed on the permissibility of ruqyah under three conditions: that it be with the words of Allah Almighty or with His Names and Attributes, and in the Arabic language or in a language whose meaning is understood, and that the rāqī believes that the ruqyah does not affect by itself but rather by the permission of Allah. It is recommended that the ruqyah be that which is transmitted, and it is permissible to perform ruqyah with any permissible duʿāʾ that contains no polytheism (shirk) or innovation (bidʿah), due to the generality of the Prophet’s (peace and blessings be upon him) saying: “There is no harm in ruqyah as long as it does not contain shirk.”