Sunan Abi Dawud Book 28, Hadith 54
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.
The Messenger of Allah(ﷺ) forbade the flesh of domestic asses on the day of Khaibar, but permitted horse flesh.
The Messenger of Allah (ﷺ) forbade us to eat horse-flesh, the flesh of mules and of asses. The narrator Haywah added: Every beast of prey with a fang.
Abu Dawud said: This view is held by Malik.
Abu Dawud said: There is no harm in (eating) horse-flesh and this tradition is not practised.
Abu Dawud said: This tradition has been abrogated. A body of Companions of the Prophet (ﷺ) had eaten horse-flesh. OF them are: Ibn al-Zubair, Fudalah bin 'Ubaid, Anas bin Malik, Asma' daughter of Abu Bakr, Suwaid bin Ghaflah, 'Alqamah; the Quraish used to slaughter them (horses) during the time of the Messenger of Allah (ﷺ).