حَدَّثَنَا سُلَيْمَانُ بْنُ حَرْبٍ، حَدَّثَنَا حَمَّادُ بْنُ زَيْدٍ، عَنْ يَحْيَى بْنِ سَعِيدٍ، عَنْ أَبِي أُمَامَةَ بْنِ سَهْلٍ، قَالَ كُنَّا مَعَ عُثْمَانَ وَهُوَ مَحْصُورٌ فِي الدَّارِ وَكَانَ فِي الدَّارِ مَدْخَلٌ مَنْ دَخَلَهُ سَمِعَ كَلاَمَ مَنْ عَلَى الْبَلاَطِ فَدَخَلَهُ عُثْمَانُ فَخَرَجَ إِلَيْنَا وَهُوَ مُتَغَيِّرٌ لَوْنُهُ فَقَالَ إِنَّهُمْ لَيَتَوَاعَدُونَنِي بِالْقَتْلِ آنِفًا ‏.‏ قُلْنَا يَكْفِيكَهُمُ اللَّهُ يَا أَمِيرَ الْمُؤْمِنِينَ ‏.‏ قَالَ وَلِمَ يَقْتُلُونَنِي سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ ‏"‏ لاَ يَحِلُّ دَمُ امْرِئٍ مُسْلِمٍ إِلاَّ بِإِحْدَى ثَلاَثٍ كُفْرٌ بَعْدَ إِسْلاَمٍ أَوْ زِنًا بَعْدَ إِحْصَانٍ أَوْ قَتْلُ نَفْسٍ بِغَيْرِ نَفْسٍ ‏"‏ ‏.‏ فَوَاللَّهِ مَا زَنَيْتُ فِي جَاهِلِيَّةٍ وَلاَ إِسْلاَمٍ قَطُّ وَلاَ أَحْبَبْتُ أَنَّ لِي بِدِينِي بَدَلاً مُنْذُ هَدَانِي اللَّهُ وَلاَ قَتَلْتُ نَفْسًا فَبِمَ يَقْتُلُونَنِي قَالَ أَبُو دَاوُدَ عُثْمَانُ وَأَبُو بَكْرٍ رضى الله عنهما تَرَكَا الْخَمْرَ فِي الْجَاهِلِيَّةِ ‏.‏

Narrated AbuUmamah ibn Sahl: We were with Uthman when he was besieged in the house. There was an entrance to the house. He who entered it heard the speech of those who were in the Bilat. Uthman then entered it. He came out to us, looking pale. He said: They are threatening to kill me now. We said: Allah will be sufficient for you against them, Commander of the Faithful! He asked: Why kill me? I heard the Messenger of Allah (PBUH) say: It is not lawful to kill a man who is a Muslim except for one of the three reasons: Kufr (disbelief) after accepting Islam, fornication after marriage, or wrongfully killing someone, for which he may be killed. I swear by Allah, I have not committed fornication before or after the coming of Islam, nor did I ever want another religion for me instead of my religion since Allah gave guidance to me, nor have I killed anyone. So for what reason do you want to kill me? Abu Dawud said: 'Uthman and Abu Bakr (Allah be pleased with them) abandoned drinking wine in pre-Islamic times. Translation Not Available

Book Ref: Sunan Abi Dawud Book 41 Hadith 4502
Web Ref:  Sunan Abi Dawud Book 40 Hadith 4487