He saw the Prophet ﷺ cutting a piece from a shoulder of mutton he was holding in his hand. He was then called to prayer, so he set it down along with the knife he had been cutting with, then stood up and prayed without performing ablution.
أنه رأى النبي ﷺ يحتز من كتف شاة- في يده، فدعي إلى الصلاة، فألقاها والسكين التي يحتز بها، ثم قام فصلى ولم يتوضأ.
Bukhari reported it in the Book of Foods (5408), and Muslim in the Book of Menstruation (355: 92), both of them through Zuhri, Jafar bin Amr bin Umaya told me that his father, Amr bin Umaya, told him, and he related it.