Musnad Ahmad 468
It was narrated that Abu Umamah bin Sahl said:
I was with ‘Uthman (رضي الله عنه) in the house when he was under siege. We would go into an entryway where, when we entered it, we could hear what the people were saying in al-Balat. `Uthman (رضي الله عنه) entered it one day for some reason, then he came out with his face flushed and said: They were threatening to kill me just now. We said: Allah will suffice you against them, O Ameer al-Mu`mineen. He said: Why would they kill me? I heard the Messenger of Allah (ﷺ) say: “It is not permissible to shed the blood of a Muslim man except in one of three cases; a man who disbelieved after having become Muslim, or a man who committed zina after being married, or a man who killed a person not in retaliation of murder But by Allah, I never committed zina either during the Jahiliyyah or in Islam... I never wanted to change my religion since Allah, may He be glorified and exalted guided me, and I never killed anyone So why do they want to kill me?
حَدَّثَنَا عَفَّانُ، حَدَّثَنَا حَمَّادُ بْنُ زَيْدٍ، حَدَّثَنَا يَحْيَى بْنُ سَعِيدٍ، عَنْ أَبِي أُمَامَةَ بْنِ سَهْلٍ، قَالَ كُنْتُ مَعَ عُثْمَانَ رَضِيَ اللَّهُ عَنْهُ فِي الدَّارِ وَهُوَ مَحْصُورٌ قَالَ وَكُنَّا نَدْخُلُ مَدْخَلًا إِذَا دَخَلْنَاهُ سَمِعْنَا كَلَامَ مَنْ عَلَى الْبَلَاطِ قَالَ فَدَخَلَ عُثْمَانُ يَوْمًا لِحَاجَةٍ فَخَرَجَ إِلَيْنَا مُنْتَقِعًا لَوْنُهُ فَقَالَ إِنَّهُمْ لَيَتَوَعَّدُونِي بِالْقَتْلِ آنِفًا قَالَ قُلْنَا يَكْفِيكَهُمُ اللَّهُ يَا أَمِيرَ الْمُؤْمِنِينَ قَالَ فَقَالَ وَبِمَ يَقْتُلُونِي فَإِنِّي سَمِعْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُولُ إِنَّهُ لَا يَحِلُّ دَمُ امْرِئٍ مُسْلِمٍ إِلَّا فِي إِحْدَى ثَلَاثٍ رَجُلٌ كَفَرَ بَعْدَ إِسْلَامِهِ أَوْ زَنَى بَعْدَ إِحْصَانِهِ أَوْ قَتَلَ نَفْسًا بِغَيْرِ نَفْسٍ فَوَاللَّهِ مَا زَنَيْتُ فِي جَاهِلِيَّةٍ وَلَا إِسْلَامٍ وَلَا تَمَنَّيْتُ بَدَلًا بِدِينِي مُذْ هَدَانِي اللَّهُ عَزَّ وَجَلَّ وَلَا قَتَلْتُ نَفْسًا فَبِمَ يَقْتُلُونِي‏.‏