Sahih Bukhari Volume 9, Book 83, Hadith Number 30.

Narrated By ‘Imran bin Husain : A man bit another man’s hand and the latter pulled his hand out of his mouth by force, causing two of his incisors (teeth) to fall out. They submitted their case to the Prophet, who said, “One of you bit his brother as a male camel bites. (Go away), there is no Diya (Blood-money) for you.”