Sayyiduna Ali (may Allah be pleased with him) said regarding Sayyiduna Ibn Abbas (may Allah be pleased with them both): This man has gone astray. Do you not know that the Messenger of Allah (peace and blessings be upon him) "forbade mut'ah marriage and eating the meat of domestic donkeys"?
(b) In al-Bukhari, the narration of Ibn Uyaynah adds that this was at the time of Khaybar, and al-Humaydi narrates from Ibn Uyaynah that this prohibition (at Khaybar) concerns eating the meat of domestic donkeys, not mut'ah marriage.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 14146