Sahih Bukhari
Food, Meals
Volume: 007 / Book Number: 065 / Hadith Number: 333
Narrated 'Amr bin Umaiyay Ad-Damri:
I saw Allah's Apostle cutting part of the shoulder of mutton with a knife. He ate of it and then was called for prayer whereupon he got up and put down the knife and offered the prayer without performing new ablution.