Chapter 2, Verse 178, The Cow
سُوۡرَةُ البَقَرَة
يَٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُواْ كُتِبَ عَلَيۡكُمُ ٱلۡقِصَاصُ فِي ٱلۡقَتۡلَىۖ ٱلۡحُرُّ بِٱلۡحُرِّ وَٱلۡعَبۡدُ بِٱلۡعَبۡدِ وَٱلۡأُنثَىٰ بِٱلۡأُنثَىٰۚ فَمَنۡ عُفِيَ لَهُۥ مِنۡ أَخِيهِ شَيۡءٞ فَٱتِّبَاعُۢ بِٱلۡمَعۡرُوفِ وَأَدَآءٌ إِلَيۡهِ بِإِحۡسَٰنٖۗ ذَٰلِكَ تَخۡفِيفٞ مِّن رَّبِّكُمۡ وَرَحۡمَةٞۗ فَمَنِ ٱعۡتَدَىٰ بَعۡدَ ذَٰلِكَ فَلَهُۥ عَذَابٌ أَلِيمٞ
O you who believe! Al-Qisas (the Law of Equality in punishment) is prescribed for you in case of murder: the free for the free, the slave for the slave, and the female for the female. But if the killer is forgiven by the brother (or the relatives, etc.) 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. This is an alleviation and a mercy from your Lord. So after this whoever transgresses the limits (i.e. kills the killer after taking the blood money), he shall have a painful torment.
Chapter 17, Verse 33, The night journey
سورة الإسراء
وَلَا تَقۡتُلُواْ ٱلنَّفۡسَ ٱلَّتِي حَرَّمَ ٱللَّهُ إِلَّا بِٱلۡحَقِّۗ وَمَن قُتِلَ مَظۡلُومٗا فَقَدۡ جَعَلۡنَا لِوَلِيِّهِۦ سُلۡطَٰنٗا فَلَا يُسۡرِف فِّي ٱلۡقَتۡلِۖ إِنَّهُۥ كَانَ مَنصُورٗا
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).
Chapter 4, Verse 92, The Women
سورة النساء
وَمَا كَانَ لِمُؤۡمِنٍ أَن يَقۡتُلَ مُؤۡمِنًا إِلَّا خَطَـٔٗاۚ وَمَن قَتَلَ مُؤۡمِنًا خَطَـٔٗا فَتَحۡرِيرُ رَقَبَةٖ مُّؤۡمِنَةٖ وَدِيَةٞ مُّسَلَّمَةٌ إِلَىٰٓ أَهۡلِهِۦٓ إِلَّآ أَن يَصَّدَّقُواْۚ فَإِن كَانَ مِن قَوۡمٍ عَدُوّٖ لَّكُمۡ وَهُوَ مُؤۡمِنٞ فَتَحۡرِيرُ رَقَبَةٖ مُّؤۡمِنَةٖۖ وَإِن كَانَ مِن قَوۡمِۭ بَيۡنَكُمۡ وَبَيۡنَهُم مِّيثَٰقٞ فَدِيَةٞ مُّسَلَّمَةٌ إِلَىٰٓ أَهۡلِهِۦ وَتَحۡرِيرُ رَقَبَةٖ مُّؤۡمِنَةٖۖ فَمَن لَّمۡ يَجِدۡ فَصِيَامُ شَهۡرَيۡنِ مُتَتَابِعَيۡنِ تَوۡبَةٗ مِّنَ ٱللَّهِۗ وَكَانَ ٱللَّهُ عَلِيمًا حَكِيمٗا
wama kana limuminin an yaqtula muminan illa khataan waman qatala muminan khataan fatahreeru raqabatin muminatin wadiyatun musallamatun ila ahlihi illa an yassaddaqoo fain kana min qawmin aaaduwwin lakum wahuwa muminun fatahreeru raqabatin muminatin wain kana min qawmin baynakum wabaynahum meethaqun fadiyatun musallamatun ila ahlihi watahreeru raqabatin muminatin faman lam yajid fasiyamu shahrayni mutatabiaaayni tawbatan mina allahi wakana allahu aaaleeman hakeeman
It is not for a believer to kill a believer except (that it be) by mistake, and whosoever kills a believer by mistake, (it is ordained that) he must set free a believing slave and a compensation (blood money, i.e. diya) be given to the deceased's family, unless they remit it. If the deceased belonged to a people at war with you and he was a believer; the freeing of a believing slave (is prescribed), and if he belonged to a people with whom you have a treaty of mutual alliance, compensation (blood money - diya) must be paid to his family, and a believing slave must be freed. And whoso finds this (the penance of freeing a slave) beyond his means, he must fast for two consecutive months in order to seek repentance from Allah. And Allah is Ever All-Knowing, All-Wise.
