(Al-Baqara) 2 : 178
يَا أَيُّهَا الَّذِينَ آمَنُوا كُتِبَ عَلَيْكُمُ الْقِصَاصُ فِي الْقَتْلَى ۖ الْحُرُّ بِالْحُرِّ وَالْعَبْدُ بِالْعَبْدِ وَالْأُنْثَىٰ بِالْأُنْثَىٰ ۚ فَمَنْ عُفِيَ لَهُ مِنْ أَخِيهِ شَيْءٌ فَاتِّبَاعٌ بِالْمَعْرُوفِ وَأَدَاءٌ إِلَيْهِ بِإِحْسَانٍ ۗ ذَٰلِكَ تَخْفِيفٌ مِنْ رَبِّكُمْ وَرَحْمَةٌ ۗ فَمَنِ اعْتَدَىٰ بَعْدَ ذَٰلِكَ فَلَهُ عَذَابٌ أَلِيمٌ
Oh, you who believed! Retaliation has been prescribed upon you in murder, the freeman for the freeman, the slave for the slave, and the female for the female; then if he is pardoned in any way by his brother, then grant well-known ransom to him and it should be in a good manner. That is Concession as well as a Mercy from your Lord; then anyone aggresses after that, then he has painful punishment.