Musnad Abu Ya'la al-Mawsili 155:276

Muhammad ibn al-Muthanna narrated to us, Abd al-Wahhab narrated to us, Muhammad ibn Amr narrated to us, from Abu Salamah, from Abu Hurayrah, who said: The Messenger of Allah (may Allah bless him and grant him peace) forbade every beast of prey with fangs, the *mujaththamah* (an animal tied up and used as a target for shooting), and the domestic donkey on the day of Khaybar.