Messenger of Allah ﷺ stood up and said: By Him besides Whom there is no god but He, the blood of a Muslim who bears the testimony that there is no god but Allah, and I am His Messenger, may be lawfully shed only in case of three persons: the one who abandons Islam, and deserts the community [Ahmad, one of the narrators, is doubtful whether the Prophet ﷺ used the word li'l-jama'ah or al-jama'ah), and the married adulterer, and life for life. (Using translation from Muslim 1676c)  

قَالَ رَسُولُ اللهِ ﷺ وَالَّذِي لَا إِلَهَ غَيْرُهُ لَا يَحِلُّ دَمُ رَجُلٍ مُسْلِمٍ يَشْهَدُ أَنْ لَا إِلَهَ إِلَّا اللهُ وَأَنِّي رَسُولُ اللهِ إِلَّا ثَلَاثَةُ نَفَرٍ التَّارِكُ لِلْإِسْلَامِ مُفَارِقُ الْجَمَاعَةِ وَالثَّيِّبُ الزَّانِي وَالنَّفْسُ بِالنَّفْسِ قَالَ الْأَعْمَشُ فَحَدَّثْتُ بِهِ إِبْرَاهِيمَ فَحَدَّثَنِي عَنِ الْأَسْوَدِ عَنْ عَائِشَةَ بِمِثْلِهِ  

[Machine] The Messenger of Allah ﷺ said, "The blood of a Muslim cannot be shed except by three: a person who commits adultery after being married, a person who renounces their faith after embracing Islam, or a person who kills another person unjustly." Zuhair narrated this hadith from Hilal bin Al-Ala, who narrated it from Hussein, who narrated it from Zuhair, who narrated it from Abu Ishaq, who narrated it from Amr bin Ghallab, who said, "Aisha said, 'O Ammar, do you not know that the shedding of a person's blood is not permissible unless for three reasons: a life for a life, or a person who commits adultery after marriage and being chaste."  

أَنَّ رَسُولَ اللهِ ﷺ قَالَ «لَا يَحِلُّ دَمُ امْرِئٍ مُسْلِمٍ إِلَّا رَجُلٌ زَنَى بَعْدَ إِحْصَانِهِ أَوْ كَفَرَ بَعْدَ إِسْلَامِهِ أَوِ النَّفْسُ بِالنَّفْسِ» وَقَفَهُ زُهَيْرٌ 3467 أَخْبَرَنَا هِلَالُ بْنُ الْعَلَاءِ قَالَ حَدَّثَنَا حُسَيْنٌ قَالَ حَدَّثَنَا زُهَيْرٌ قَالَ حَدَّثَنَا أَبُو إِسْحَاقَ عَنْ عَمْرِو بْنِ غَالِبٍ قَالَ قَالَتْ عَائِشَةُ يَا عَمَّارُ أَمَا إِنَّكَ تَعْلَمُ أَنَّهُ لَا يَحِلُّ دَمُ امْرِئٍ إِلَّا ثَلَاثَةٌ نَفْسٌ بِنَفْسٍ أَوْ رَجُلٌ زَنَى بَعْدَمَا أُحْصِنَ  

"We were with 'Uthman when he was under siege and we could hear what was said from Al-Balat. 'Uthman came in one day, then he came out, and said: 'They are threatening to kill me.' We said: 'Allah will suffice you against them.' He said: 'Why would they kill me? I heard the Messenger of Allah [SAW] say: It is not permissible to shed the blood of a Muslim except in one of three cases: A man who reverts to Kufr after becoming Muslim, or commits adultery after being married, or one who kills a soul unlawfully. By Allah, I did not commit adultery during Jahiliyyah or in Islam, I never wished to follow any other religion since Allah guided me, and I have never killed anyone, so why do they want to kill me?'" (Using translation from Nasāʾī 4019)  

نَسْمَعُ كَلَامَ مَنْ بِالْبَلَاطِ فَدَخَلَ عُثْمَانُ يَوْمًا ثُمَّ خَرَجَ مُتَغَيِّرًا لَوْنُهُ فَقَالَ إِنَّهُمْ لَيَتَوَاعَدُونِّي بِالْقَتْلِ قُلْنَا يَكْفِيكَهُمُ اللهُ قَالَ وَلِمَ يَقْتُلُونِّي؟ سَمِعْتُ رَسُولَ اللهِ ﷺ يَقُولُ لَا يَحِلُّ دَمُ امْرِئٍ مُسْلِمٍ إِلَّا بِإِحْدَى ثَلَاثٍ رَجُلٌ كَفَرَ بَعْدَ إِسْلَامِهِ أَوْ زَنَى بَعْدَ إِحْصَانِهِ أَوْ قَتَلَ نَفْسًا بِغَيْرِ نَفْسٍ فَوَاللهِ مَا زَنَيْتُ فِي جَاهِلِيَّةٍ وَلَا إِسْلَامٍ قَطُّ وَلَا تَمَنَّيْتُ أَنَّ لِي بِدِينِي بَدَلًا مُنْذُ هَدَانِيَ اللهُ وَلَا قَتَلْتُ نَفْسًا فَبِمَ يَقْتُلُونِي؟