أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ عُبَيْدِ بْنِ عَقِيلٍ، قَالَ حَدَّثَنَا جَدِّي، قَالَ حَدَّثَنَا شُعْبَةُ، عَنِ الْحَكَمِ، عَنْ مُجَاهِدٍ، عَنْ يَعْلَى ابْنِ مُنْيَةَ، أَنَّ رَجُلاً، مِنْ بَنِي تَمِيمٍ قَاتَلَ رَجُلاً فَعَضَّ يَدَهُ فَانْتَزَعَهَا فَأَلْقَى ثَنِيَّتَهُ فَاخْتَصَمَا إِلَى رَسُولِ اللَّهِ صلى الله عليه وسلم فَقَالَ ‏"‏ يَعَضُّ أَحَدُكُمْ أَخَاهُ كَمَا يَعَضُّ الْبَكْرُ ‏"‏ ‏.‏ فَأَطَلَّهَا أَىْ أَبْطَلَهَا ‏.‏

It was narrated from Ya'la bin Munyah that: a man from Banu Tamim fought with another man, and he bit his hand, so he pulled it away and a front tooth fell out. They referred the dispute to the Messenger of Allah, who said: "Would one of you bite his brother as a young camel bites?" and he thwarted it, meaning he judged it to be invalid. Translation Not Available

Book Ref: Sunan An Nisai Book 45 Hadith 4764
Web Ref:  Sunan An Nisai Vol 5 Book 45 Hadith 4768