Sunan Ibn Majah, Book 31, Hadith 3595 (In-Book) ⓘ
It was narrated from ‘Amr bin Shu’aib, from his father, that his grandfather said: “The Messenger of Allah said: ‘Whoever gives medical treatment, with no prior knowledge of medicine, is responsible (for any harm done).’”
حَدَّثَنَا هِشَامُ بْنُ عَمَّارٍ، وَرَاشِدُ بْنُ سَعِيدٍ الرَّمْلِيُّ، قَالاَ حَدَّثَنَا الْوَلِيدُ بْنُ مُسْلِمٍ، حَدَّثَنَا ابْنُ جُرَيْجٍ، عَنْ عَمْرِو بْنِ شُعَيْبٍ، عَنْ أَبِيهِ، عَنْ جَدِّهِ، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ " مَنْ تَطَبَّبَ وَلَمْ يُعْلَمْ مِنْهُ طِبٌّ قَبْلَ ذَلِكَ فَهُوَ ضَامِنٌ " .
also referenced under: Hadith 3466 (Reference) & Volume 4, Book 31, Hadith 3466 (DarusSalam)