مُسْنَدُ أَحْمَدَ
Musnad Ahmad 3995
Musnad of Abdullah bin Mas'ood
It was narrated that Ibn Mas'ood said: Some people came to the Prophet (ﷺ) and said: O Messenger of Allah, our companion is sick, can we cauterise him? He remained silent for a while, then he said: "If you wish you could cauterise him or if you wish you could use hot stones."
Musnad Ahmad 4021A saheeh hadeeth]