´It was narrated that ‘Imran bin Husain said:` “The Messenger of Allah (ﷺ) forbade cauterization. I had myself cauterized and I have not prospered or succeeded.”
1؎: This is a tanzihi (discouraged but not sinful) prohibition, meaning it is considered contrary to what is preferable. This is because the Prophet sallallahu alayhi wa sallam himself cauterized Sa'd ibn Mu'adh and As'ad ibn Zurarah radi Allahu anhuma with his own hand; had it been forbidden (haram), he would not have done so. The reason for its dislike is that it is a punishment by fire, which is something exclusive to Allah, Lord of the worlds. Therefore, refraining from this act is more appropriate and superior.
´Imran bin Husain narrated that the Messenger of Allah (s.a.w) prohibited cauterization. He said:` "We were tested (with severe medical condition) so we were cauterized, but we did not have good results, nor was it successful for us." Another chain reports a similar narration.
Shaykh Dr. Abdur Rahman Freywai
Explanation: 1: The prohibition of cauterization for treatment is to be understood as being of a non-emphatic (tanzihi) nature, meaning that it is better not to cauterize. One opinion is also that this prohibition is specific to Imran bin Husayn (radi Allahu anhu), because it is possible that he was afflicted with such an illness in which cauterizing the body would have caused him harm rather than benefit. See the next hadith.
Source: Sunan al-Tirmidhi – Majlis ‘Ilmi Dar al-Da‘wah, New Delhi Edition, Page: 2049