The Book of Hunting and Slaughtering
42/32. Chapter:
Permissibility Of Eating The Flesh Of Onagers (Wild Donkeys)
Sunan an-Nasai
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا الْمُفَضَّلُ، - هُوَ ابْنُ فَضَالَةَ - عَنِ ابْنِ جُرَيْجٍ، عَنْ أَبِي الزُّبَيْرِ، عَنْ جَابِرٍ، قَالَ أَكَلْنَا يَوْمَ خَيْبَرَ لُحُومَ الْخَيْلِ وَالْوَحْشِ وَنَهَانَا النَّبِيُّ صلى الله عليه وسلم عَنِ الْحِمَارِ .
It was narrated that Jabir said: "On the Day of Khaibar we ate the flesh of horses, and onagers, but the Prophet forbade us (from eating) donkeys."(sahih)
Reference : Sunan an-Nasa'i 4343In-book reference : Book 42, Hadith 81English translation : Vol. 5, Book 42, Hadith 4348