If a person attacks another person's life and limb, and the other defends himself and kills him or injures him, there is no penalty on him
حَدَّثَنَا شَيْبَانُ بْنُ فَرُّوخَ، حَدَّثَنَا هَمَّامٌ، حَدَّثَنَا عَطَاءٌ، عَنْ صَفْوَانَ بْنِ يَعْلَى ابْنِ، مُنْيَةَ عَنْ أَبِيهِ، قَالَ أَتَى النَّبِيَّ صلى الله عليه وسلم رَجُلٌ وَقَدْ عَضَّ يَدَ رَجُلٍ فَانْتَزَعَ يَدَهُ فَسَقَطَتْ ثَنِيَّتَاهُ - يَعْنِي الَّذِي عَضَّهُ - قَالَ فَأَبْطَلَهَا النَّبِيُّ صلى الله عليه وسلم وَقَالَ " أَرَدْتَ أَنْ تَقْضَمَهُ كَمَا يَقْضَمُ الْفَحْلُ " .
Safwan b. Ya'la b. Munya reported on the authority of his father that there came to Allah's Messenger (ﷺ) a person who had bitten the hand of another person and who had withdrawn his hand (and as a result thereof) his foreteeth had fallen (those which had bitten). The Messenger of Allah (ﷺ) turned down his (claim), and said: Do you wish to bite as the camel bites?