Al-Isra 17:33

<h2>Prohibition of Unlawful Killing Allah forbids killing with no legitimate reason</h2><p>It was reported in the Two Sahihs that the Messenger of Allah ﷺ said:</p><p>«لَا يَحِلُّ دَمُ امْرِىءٍ مُسْلِمٍ يَشْهَدُ أَنْ لَا إِلَهَ إِلَّا اللهُ وَأَنَّ مُحَمَّدًا رَسُولُ اللهِ، إِلَّا بِإِحْدَى ثَلَاثٍ: النَّفْسُ بِالنَّفْسِ، وَالزَّانِي الْمُحْصَنُ، وَالتَّارِكُ لِدِينِهِ الْمُفَارِقُ لِلْجَمَاعَة»</p><p>(The blood of a Muslim who bears witness to La ilaha illallah and that Muhammad ﷺ is the Messenger of Allah, is not permissible (to be shed) except in three cases: a soul for a soul (i.e., in the case of murder), an adulterer who is married, and a person who leaves his religion and deserts the Jama'ah.) The following is recorded in the books of the Sunan:</p><p>«لَزَوَالُ الدُّنْيَا عِنْدَ اللهِ أَهْوَنُ مِنْ قَتْلِ مُسْلِم»</p><p>(If the world were to be destroyed, it would be of less importance to Allah than the killing of a Muslim.)</p><p>وَمَن قُتِلَ مَظْلُومًا فَقَدْ جَعَلْنَا لِوَلِيِّهِ سُلْطَـناً</p><p>(And whoever is killed wrongfully, We have given his heir the authority.) The authority is over the killer. The heir has the choice; if he wishes, he may have him killed in retaliation, or he may forgive him in return for the payment of the Diyah (blood money), or he may forgive …

And slay not the life which Allah hath forbidden save with right. Whoso is slain wrongfully, We have given power unto his heir, but let him not commit excess in slaying. Lo! he will be helped.

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).

And do not kill anyone which Allah has forbidden, except for a just cause. And whoever is killed (intentionally with hostility and oppression and not by mistake), We have given his heir the authority [(to demand Qisas, Law of Equality in punishment or to forgive, or to take Diya (blood money)]. But let him not exceed limits in the matter of taking life (i.e. he should not kill except the killer only). Verily, he is helped (by the Islamic law).

And do not kill the soul which God has made sacred, except in the course of justice. If someone is killed unjustly, We have given his next of kin certain authority. But he should not be excessive in killing, for he will be supported.