Language:
كتاب المغازى
64  
Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)
(38)
Chapter: Ghazwa of Khaibar
(38)
باب غَزْوَةُ خَيْبَرَ
Sahih al-Bukhari 4199

Narrated Anas bin Malik:

Someone came to Allah's Messenger (ﷺ)s and said, "The donkeys have been eaten (by the Muslims)." The Prophet kept quiet. Then the man came again and said, "The donkeys have been eaten." The Prophet (ﷺ) kept quiet. The man came to him the third time and said, "The donkeys have been consumed." On that the Prophet (ﷺ) ordered an announcer to announce to the people, "Allah and His Apostle forbid you to eat the meat of donkeys." Then the cooking pots were upset while the meat was still boiling in them.

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ عَبْدِ الْوَهَّابِ، حَدَّثَنَا عَبْدُ الْوَهَّابِ، حَدَّثَنَا أَيُّوبُ، عَنْ مُحَمَّدٍ، عَنْ أَنَسِ بْنِ مَالِكٍ ـ رضى الله عنه أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم جَاءَهُ جَاءٍ فَقَالَ أُكِلَتِ الْحُمُرُ‏.‏ فَسَكَتَ، ثُمَّ أَتَاهُ الثَّانِيَةَ فَقَالَ أُكِلَتِ الْحُمُرُ‏.‏ فَسَكَتَ، ثُمَّ الثَّالِثَةَ فَقَالَ أُفْنِيَتِ الْحُمُرُ‏.‏ فَأَمَرَ مُنَادِيًا فَنَادَى فِي النَّاسِ إِنَّ اللَّهَ وَرَسُولَهُ يَنْهَيَانِكُمْ عَنْ لُحُومِ الْحُمُرِ الأَهْلِيَّةِ‏.‏ فَأُكْفِئَتِ الْقُدُورُ، وَإِنَّهَا لَتَفُورُ بِاللَّحْمِ‏.‏
Reference : Sahih al-Bukhari 4199
In-book reference : Book 64, Hadith 239
USC-MSA web (English) reference : Vol. 5, Book 59, Hadith 511
  (deprecated numbering scheme)