Musnad Abu Ya'la al-Mawsili 109:156

Zuhayr narrated to us, Abd al-Rahman ibn Mahdi narrated to us, Hammad ibn Zayd narrated to us, from Amr ibn Dinar, from Muhammad ibn Ali, from Jabir: That the Messenger of Allah (may Allah bless him and grant him peace) forbade on the day of Khaybar the meat of domestic donkeys, and he permitted the meat of horses.