Musnad Ahmad 5:250

'Abdullah narrated to us, Muhammad ibn Abi Bakr al-Muqaddami narrated to me, Hammad ibn Zayd narrated to us, Ma'mar narrated to us, from al-Zuhri, from 'Abdullah ibn Muhammad ibn 'Ali, from 'Ali: "That the Prophet, peace and blessings of Allah be upon him, forbade on the day of Khaybar [temporary] marriage (mut'ah) and the meat of donkeys."