Sahih al-Bukhari 4226
Sahih al-Bukhari · Book 64: Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi) · Ghazwa of Khaibar
Narrated Al-Bara Bin Azib:
حَدَّثَنِي إِبْرَاهِيمُ بْنُ مُوسَى ، أَخْبَرَنَا ابْنُ أَبِي زَائِدَةَ ، أَخْبَرَنَا عَاصِمٌ ، عَنْ عَامِرٍ ، عَنِ الْبَرَاءِ بْنِ عَازِبٍ ـ رضى الله عنهما ـ قَالَ أَمَرَنَا النَّبِيُّ صلى الله عليه وسلم فِي غَزْوَةِ خَيْبَرَ أَنْ نُلْقِيَ الْحُمُرَ الأَهْلِيَّةَ نِيئَةً وَنَضِيجَةً، ثُمَّ لَمْ يَأْمُرْنَا بِأَكْلِهِ بَعْدُ.
During the Ghazwa of Khaibar, the Prophet (ﷺ) ordered us to throw away the meat of the donkeys whether it was still raw or cooked. He did not allow us to eat it later on.