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.
Sunan Abi Dawud Book 41, Hadith 93
← Previous Hadith The Prophet (ﷺ) said to the man bit him: If you wish that you give him control over your hand and he bites it, and then you drive it away from his mouth (you may do it). He imposed no retaliation for his teeth.

Sunan Abi Dawud Book 41, Hadith 92 Next Hadith → 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.

Sunan Abi Dawud Book 41, Hadith 94