Answer:

1. You who believe! Al-Qisas (the Law of Equality in punishment) is prescribed for you in case of murder: the free for free, the slave for slave, and the female for female. But if the killer is forgiven by the brother (or the relatives) of the killed against blood money, then adhering to it with fairness and payment of the blood money to the heir should be made in fairness. So after this whoever transgresses the limits (i.e. kills the killer after taking the blood money), he shall have a painful torment. (2:178)
2. In the Law of Equality there is (saving of) Life to you, O you men of understanding; that you may restrain yourselves. (2:179)

Answer:

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 nor exceed bounds in the matter of taking life; for he is helped (by the Law). (17:33)

Answer:

As for anyone who kills a believer deliberately, his repayment is Hell, remaining in it timelessly, forever. Allah is angry with him and has cursed him, and has prepared for him a terrible punishment. (4:93)

Answer:

A believer should never kill another believer unless it is by mistake. Anyone who kills a believer by mistake should free a believing slave and pay blood-money to his family unless they forgo it as a charity. If he is from a people who are your enemies and is a believer, you should free a believing slave. If he is from a people you have a treaty with, blood money should be paid to his family and you should free a believing slave. Anyone who cannot find the means should fast two consecutive months. This is a concession from Allah. Allah is All-Knowing, All-Wise. (4:92)