Sunan an-Nasā'ī 4830✓ 3Hasan
أَخْبَرَنِي عَمْرُو بْنُ عُثْمَانَ، وَمُحَمَّدُ بْنُ مُصَفًّى، قَالاَ حَدَّثَنَا الْوَلِيدُ، عَنِ ابْنِ جُرَيْجٍ، عَنْ عَمْرِو بْنِ شُعَيْبٍ، عَنْ أَبِيهِ، عَنْ جَدِّهِ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنْ تَطَبَّبَ وَلَمْ يُعْلَمْ مِنْهُ طِبٌّ قَبْلَ ذَلِكَ فَهُوَ ضَامِنٌ " .
It was narrated from'Amrbin shu'aib, from his father that his grandfather said:"the Messenger of Allah said: 'Whoever practices medicine when he is not known for that, he is liable.