(6) باب قَوْلِ اللَّهِ تَعَالَى {أَنَّ النَّفْسَ بِالنَّفْسِ وَالْعَيْنَ بِالْعَيْنِ وَالأَنْفَ بِالأَنْفِ وَالأُذُنَ بِالأُذُنِ وَالسِّنَّ بِالسِّنِّ وَالْجُرُوحَ قِصَاصٌ فَمَنْ تَصَدَّقَ بِهِ فَهُوَ كَفَّارَةٌ لَهُ وَمَنْ لَمْ يَحْكُمْ بِمَا أَنْزَلَ اللَّهُ فَأُولَئِكَ هُمُ الظَّالِمُونَ}
Narrated `Abdullah:
Allah's Messenger (ﷺ) said, "The blood of a Muslim who confesses that none has the right to be worshipped but Allah and that I am His Apostle, cannot be shed except in three cases: In Qisas for murder, a married person who commits illegal sexual intercourse and the one who reverts from Islam (apostate) and leaves the Muslims."
Reference: Sahih al-Bukhari 6878
In-book reference: Book 87, Hadith 17
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 9, Book 83, Hadith 17