The Book of Prayers (Kitab Al-Salat)
Muslim :: Book 4 : Hadith 1304
Rafi' b. Khadij reported: We used to say the afternoon prayer with the Messenger of Allah (may peace be upon him), and then the camel was slaughtered and ten parts of it were distributed; then it was cooked and then we ate this cooked meat before the sinking of the sun.