2:178
O you who believe[d]! Prescribed for you (is) the legal retribution in (the matter of) the murdered, the freeman for the freeman, and the slave for the slave, and the female for the female. But whoever is pardoned [for it] from his brother anything, then follows up with suitable [and] payment to him with kindness. That (is) a concession from your Lord and mercy. Then whoever transgresses after that, then for him (is) a punishment painful.