Musnad Ahmad 26:471

'Abd al-Razzaq narrated to us, Ma'mar narrated to us, from Abu Ishaq, from Abu al-Ahwas, from Ibn Mas'ud, who said: A group of people came to the Prophet, may Allah bless him and grant him peace, and said: "O Messenger of Allah, a companion of ours is ill, shall we cauterize him?" He remained silent for a moment, then said: "If you wish, cauterize him, and if you wish, treat him with a heated stone."