Sunan an-Nasa'i 4409

It was narrated that Rafi said:"I said: 'O Messenger of Allah, we are going to meet the enemy tomorrow, and we do not have any knives.' He said: 'If the blood is shed and the name of Allah is mentioned, then eat, unlike (it is slaughtered) with teeth or nails." Then the Messenger of Allah got some spoils of war and a camel ran away. A man shot and arrow at it and stopped it. He (the Prophet) said; 'Some of these animals - or 'these camels'- 'are untamed like wild animals, so if one of them goes out of your control, do the same."' (Sahih)