Al-Baqarah 2:178 يا ايها الذين امنوا كتب عليكم القصاص في القتلى الحر بالحر والعبد بالعبد والانثى بالانثى فمن عفي له من اخيه شيء فاتباع بالمعروف واداء اليه باحسان ذالك تخفيف من ربكم ورحمة فمن اعتدى بعد ذالك فله عذاب اليم ١٧٨

O ye who believe! Retaliation is prescribed for you in the matter of the murdered; the freeman for the freeman, and the slave for the slave, and the female for the female. And for him who is forgiven somewhat by his (injured) brother, prosecution according to usage and payment unto him in kindness. This is an alleviation and a mercy from your Lord. He who transgresseth after this will have a painful doom.