Abu Dawud Book 9, Hadith Number 2818.
Chapter : On slaughtering an animal with a sharp white stone used as a knife flint.
Narated By Adi ibn Hatim : I said: Apostle of Allah, tell me when one of us catches game and has no knife; may he slaughter with a flint and a splinter of stick. He said: Cause the blood to flow with whatever you like and mention Allah’s name.