"Al-Qisas (the Law of Equality in punishment) is prescribed for you in case of murder: the free for the free[2] The rule for the Children of Israel was Qisas, and not Diyah. Then Allah, the Mighty and Sublime, revealed the Diyah to them, and He revealed this ruling to this Ummah as an alleviation of the ruling that applied to the Children of Israel." (Using translation from Nasāʾī 4782)
{كُتِبَ عَلَيْكُمُ الْقِصَاصُ فِي الْقَتْلَى الْحَرُّ بِالْحُرِّ} [البقرة 178] قَالَ كَانَ بَنُو إِسْرَائِيلَ عَلَيْهِمُ الْقِصَاصُ وَلَيْسَ عَلَيْهِمُ الدِّيَةُ «فَأَنْزَلَ اللهُ الدِّيَةَ فَجَعَلَهَا عَلَى هَذِهِ الْأُمَّةِ تَخْفِيفًا عَلَى مَا كَانَ عَلَى بَنِي إِسْرَائِيلَ»