Sahih al-Bukhari 6892
Narrated `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."
حَدَّثَنَا آدَمُ، حَدَّثَنَا شُعْبَةُ، حَدَّثَنَا قَتَادَةُ، قَالَ سَمِعْتُ زُرَارَةَ بْنَ أَوْفَى، عَنْ عِمْرَانَ بْنِ حُصَيْنٍ، أَنَّ رَجُلاً، عَضَّ يَدَ رَجُلٍ، فَنَزَعَ يَدَهُ مِنْ فَمِهِ، فَوَقَعَتْ ثَنِيَّتَاهُ، فَاخْتَصَمُوا إِلَى النَّبِيِّ صلى الله عليه وسلم فَقَالَ ‏
"‏ يَعَضُّ أَحَدُكُمْ أَخَاهُ كَمَا يَعَضُّ الْفَحْلُ، لاَ دِيَةَ لَكَ ‏"‏‏.‏