Surah Al-Isra' (The Night Journey), Verse 33

وَلَا تَقْتُلُوا النَّفْسَ الَّتِیْ حَرَّمَ اللّٰهُ اِلَّا بِالْحَقِّ وَمَنْ قُتِلَ مَظْلُوْمًا فَقَدْ جَعَلْنَا لِوَلِیِّهٖ سُلْطٰنًا فَلَا یُسْرِفْ فِّی الْقَتْلِ اِنَّهٗ كَانَ مَنْصُوْرًا ۟

Wa laa taqtulun nafsal latee harramal laahu illaa bilhaqq; wa man qutila mazlooman faqad ja'alnaa liwaliyyihee sultaanan falaa yusrif fil qatli innahoo kaana mansooraa

“Nor take life - which Allah has made sacred - except for just cause. And if anyone is slain wrongfully, we have given his heir authority (to demand qisas or to forgive): but let him not exceed bounds in the matter of taking life; for he is helped (by the Law).”

Quran 17:33 (Yusuf Ali Translation)