Sahih Bukhari Volume 008, Book 075, Hadith Number 343.

Narated By Salama bin Al-Akwa' : We went out with the Prophet to Khaibar. A man among the people said, "O 'Amir! Will you please recite to us some of your poetic verses?" So 'Amir got down and started chanting among them, saying, "By Allah! Had it not been for Allah, we would not have been guided." 'Amir also said other poetic verses which I do not remember. Allah's Apostle said, "Who is this (camel) driver?" The people said, "He is 'Amir bin Al-Akwa'," He said, "May Allah bestow His Mercy on him." A man from the People said, "O Allah's Apostle! Would that you let us enjoy his company longer." When the people (Muslims) lined up, the battle started, and 'Amir was struck with his own sword (by chance) by himself and died. In the evening, the people made a large number of fires (for cooking meals). Allah's Apostle said, "What is this fire? What are you making the fire for?" They said, "For cooking the meat of donkeys." He said, "Throw away what is in the pots and break the pots!" A man said, "O Allah's Prophet! May we throw away what is in them and wash them?" He said, "Never mind, you may do so." (See Hadith No. 509, Vol. 5).