Surah Al-Isra Verse 33 - English Translation by Ahmed Ali
Surah Al-Israوَلَا تَقۡتُلُواْ ٱلنَّفۡسَ ٱلَّتِي حَرَّمَ ٱللَّهُ إِلَّا بِٱلۡحَقِّۗ وَمَن قُتِلَ مَظۡلُومٗا فَقَدۡ جَعَلۡنَا لِوَلِيِّهِۦ سُلۡطَٰنٗا فَلَا يُسۡرِف فِّي ٱلۡقَتۡلِۖ إِنَّهُۥ كَانَ مَنصُورٗا
And do not take a life, which God has forbidden, except in a just cause. We have given the right (of redress) to the heir of the person who is killed, but he should not exceed the limits (of justice) by slaying (the killer), for he will be judged (by the same law)