Sahih al-Bukhari 87:17
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 87:17
In-book reference
Book 87, Hadith 17
Arabic Text
حَدَّثَنَا عُمَرُ بْنُ حَفْصٍ، حَدَّثَنَا أَبِي، حَدَّثَنَا الأَعْمَشُ، عَنْ عَبْدِ اللَّهِ بْنِ مُرَّةَ، عَنْ مَسْرُوقٍ، عَنْ عَبْدِ اللَّهِ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " لاَ يَحِلُّ دَمُ امْرِئٍ مُسْلِمٍ يَشْهَدُ أَنْ لاَ إِلَهَ إِلاَّ اللَّهُ وَأَنِّي رَسُولُ اللَّهِ إِلاَّ بِإِحْدَى ثَلاَثٍ النَّفْسُ بِالنَّفْسِ وَالثَّيِّبُ الزَّانِي، وَالْمَارِقُ مِنَ الدِّينِ التَّارِكُ الْجَمَاعَةَ ".