Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
quran:42:39 –

And those who, when tyranny strikes them, they defend themselves,  

and those who, when they suffer aggression, injustice, defend themselves — these are another category — that is to say, they retaliate against those who wrong them in the same manner in which the latter wronged them, as God, exalted be He, says:
القرآن:٤٢:٣٩ –

وَالَّذِينَ إِذَا أَصَابَهُمُ الْبَغْيُ هُمْ يَنْتَصِرُونَ  

{والذين إذا أصابهم البغي} الظلم {هم ينتصرون} صنف، أي ينتقمون ممن ظلمهم بمثل ظلمه، كما قال تعالى: