Sayyiduna Rafi' bin Khadij (may Allah be pleased with him) says: We were with the Messenger of Allah (peace and blessings be upon him) on a military expedition, and we said: Tomorrow morning we will attack the enemy and we have no knives. The Messenger of Allah (peace and blessings be upon him) said: "Whatever makes the blood flow and over which the name of Allah is mentioned, eat it, as long as it is not a tooth or a nail, for the tooth is bone, and the nail is the knife of the Abyssinians."
Hadith Referenceالمعجم الكبير للطبراني / باب الراء / 4379