Sahih Muslim 2118
Sahih Muslim · Book 37: The Book of Clothes and Adornment · The Prohibition Of Striking Or Branding Animals On The Face
Ibn Abbas reported that Allah's Messenger (ﷺ) saw an ass which had been cauterised on the face. He disapproved of it saying:
حَدَّثَنَا أَحْمَدُ بْنُ عِيسَى ، أَخْبَرَنَا ابْنُ وَهْبٍ ، أَخْبَرَنِي عَمْرُو بْنُ الْحَارِثِ ، عَنْ يَزِيدَ، بْنِ أَبِي حَبِيبٍ أَنَّ نَاعِمًا أَبَا عَبْدِ اللَّهِ ، مَوْلَى أُمِّ سَلَمَةَ حَدَّثَهُ أَنَّهُ، سَمِعَ ابْنَ عَبَّاسٍ ، يَقُولُ وَرَأَى رَسُولُ اللَّهِ صلى الله عليه وسلم حِمَارًا مَوْسُومَ الْوَجْهِ فَأَنْكَرَ ذَلِكَ قَالَ فَوَاللَّهِ لاَ أَسِمُهُ إِلاَّ فِي أَقْصَى شَىْءٍ مِنَ الْوَجْهِ . فَأَمَرَ بِحِمَارٍ لَهُ فَكُوِيَ فِي جَاعِرَتَيْهِ فَهُوَ أَوَّلُ مَنْ كَوَى الْجَاعِرَتَيْنِ .
By Allah, I do not cauterise (the animal) but on a part at a distance from the face, and commanded (for the cauterisation) of his ass and it was cauterised on the buttocks and he was the first to cauterise on the buttocks.