Sunan Abu Dawud
3789
Sahih+2

Narrated Jabir ibn Abdullah: On the day of Khaybar we slaughtered horses, mules, and assess. The Messenger of Allah (ﷺ) forbade us (to eat) mules and asses, but he did not forbid horse-flesh

SahihAl-Albani
SahihMuhammad Muhyi Al-Din Abdul Hamid