On his father's authority, said that his grandfather reported the Messenger of Allah ﷺ said: Anyone who practises medicine when he is not known as a practitioner will be held responsible. Abu Dawud said: This has been transmitted by al-Walid alone. We do not know whether it is sound or not.  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ مَنْ تَطَبَّبَ وَلاَ يُعْلَمُ مِنْهُ طِبٌّ فَهُوَ ضَامِنٌ قَالَ نَصْرٌ قَالَ حَدَّثَنِي ابْنُ جُرَيْجٍ  

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.  

حَدَّثَنِي بَعْضُ الْوَفْدِ الَّذِينَ قَدِمُوا عَلَى أَبِي قَالَ قَالَ رَسُولُ اللَّهِ ﷺ 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