Hadith 1676 a - The Book of Oaths, Muharibin, Qasas (Retaliation), and Diyat (Blood Money) - Sahih Muslim - صحيح مسلم - Collection of Actions, Sayings and Teachings of Prophet Muhammad (صلى الله عليه و سلم) - Kutub as-Sittah

28. The Book of Oaths, Muharibin, Qasas (Retaliation), and Diyat (Blood Money) - كتاب القسامة والمحاربين والقصاص والديات

6) Chapter: When it is permissible to shed the blood of a muslim

'Abdullah (b. Mas'ud) reported Allah's Messenger (ﷺ) as saying:

It is not permissible to take the life of a Muslim who bears testimony (to the fact that there is no god but Allah, and I am the Messenger of Allah, but in one of the three cases: the married adulterer, a life for life, and the deserter of his Din (Islam), abandoning the community.

Reference: 1676 a
English reference: Book 16, Hadith 4152
In-book reference: Book 28, Hadith 34
Grade: Sahih
Read this hadith from Darussalam Collection

6) باب مَا يُبَاحُ بِهِ دَمُ الْمُسْلِمِ ‏‏

حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا حَفْصُ بْنُ غِيَاثٍ، وَأَبُو مُعَاوِيَةَ وَوَكِيعٌ عَنِ الأَعْمَشِ، 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 الثَّيِّبُ الزَّانِ وَالنَّفْسُ بِالنَّفْسِ وَالتَّارِكُ لِدِينِهِ الْمُفَارِقُ لِلْجَمَاعَةِ ‏"