Sahih Bukhari
Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)
Volume: 005 / Book Number: 059 / Hadith Number: 527
Narrated 'Ali bin Abi Talib:
On the day of Khaibar, Allah's Apostle forbade the Mut'a (i.e. temporary marriage) and the eating of donkey-meat.