Sahih Bukhari Volume 7, Book 65, Hadith Number 316.

Narrated By Ibn ‘Abbas : The Prophet ate of the meat of a shoulder (by cutting the meat with his teeth), and then got up and offered the prayer without performing the ablution anew. Narrated Ibn ‘Abbas: The Prophet took out a bone with meat on it from a cooking pot and ate of it, and then offered the prayer without performing ablution anew.