Narrated AbdulAziz ibn Umar ibn AbdulAziz:

Some people of the deputation which came to my father reported the Messenger of Allah (ﷺ) as saying: Any physician who practises medicine when he was not known as a practitioner before that and he harms (the patients) he will be held responsible. AbdulAziz said: Here physician does not refer to a man by qualification. it means opening a vein, incision and cauterisation.

حَدَّثَنَا مُحَمَّدُ بْنُ الْعَلاَءِ، حَدَّثَنَا حَفْصٌ، حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ عُمَرَ بْنِ عَبْدِ الْعَزِيزِ، حَدَّثَنِي بَعْضُ الْوَفْدِ الَّذِينَ، قَدِمُوا عَلَى أَبِي قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏

‏ أَيُّمَا طَبِيبٍ تَطَبَّبَ عَلَى قَوْمٍ لاَ يُعْرَفُ لَهُ تَطَبُّبٌ قَبْلَ ذَلِكَ فَأَعْنَتَ فَهُوَ ضَامِنٌ ‏

‏ ‏.‏ قَالَ عَبْدُ الْعَزِيزِ أَمَا إِنَّهُ لَيْسَ بِالنَّعْتِ إِنَّمَا هُوَ قَطْعُ الْعُرُوقِ وَالْبَطُّ وَالْكَىُّ ‏.‏