Surah Al-Isra Verse 33 - English Translation by Ali Unal
Surah Al-Israوَلَا تَقۡتُلُواْ ٱلنَّفۡسَ ٱلَّتِي حَرَّمَ ٱللَّهُ إِلَّا بِٱلۡحَقِّۗ وَمَن قُتِلَ مَظۡلُومٗا فَقَدۡ جَعَلۡنَا لِوَلِيِّهِۦ سُلۡطَٰنٗا فَلَا يُسۡرِف فِّي ٱلۡقَتۡلِۖ إِنَّهُۥ كَانَ مَنصُورٗا
Do not kill any soul, which God has made forbidden, except in just cause. If anyone has been killed wrongfully and intentionally, We have given his heir (as defender of his rights) the authority (to claim retaliation or damages or to forgive outright). But let him (the heir) not exceed the legitimate bounds in (retaliatory) killing. Indeed he has been helped (already and sufficiently by the provisions and procedures of the Law)