It was narrated that Ya'la and Salamah the sons of Umayyah said: "We went out with the Messenger of Allah on the military expedition of Tabuk, and with us was a friend of ours. He fought with another man while we were on the road. The man bit the hand of his opponent, who pulled away his hand and the man's tooth fell out. He came to the Messenger of Allah demanding compensatory money for his tooth, and the Messenger of Allah said: 'Would anyone of you go and bite his brother like a stallion, then come demanding compensatory money? There is no compensatory money for this.’ Hence, the Messenger of Allah invalidated it (i.e. compensatory money in such a case).