Al-Adab Al-Mufrad, Book 30, Hadith 603 (English) ⓘ

'A'isha said, "The Prophet was lying down in my room with his thigh uncovered when Abu Bakr asked for permission to enter. He gave him permission to enter, remaining as he was. Then 'Umar asked for permission to come in and he gave him permission, remaining as he was. Then 'Uthman asked for permission to enter and the Prophet, may Allah bless him and grant him peace, sat up and arranged his garment, and then he came in and spoke. When he left, I said, 'Messenger of Allah, Abu Bakr came in and you did not exert yourself nor concern yourself with him. Then 'Umar came in and you did not exert yourself nor concern yourself with him. Then 'Uthman came in and you sat up and arranged your garment.' He said, 'Should I not be modest before a man before whom the angels are modest?'"

حَدَّثَنَا أَبُو الرَّبِيعِ قَالَ‏:‏ حَدَّثَنِي إِسْمَاعِيلُ قَالَ‏:‏ حَدَّثَنِي مُحَمَّدُ بْنُ أَبِي حَرْمَلَةَ، عَنْ عَطَاءٍ وَسُلَيْمَانَ ابْنَيْ يَسَارٍ، وَأَبِي سَلَمَةَ بْنِ عَبْدِ الرَّحْمَنِ، أَنَّ عَائِشَةَ قَالَتْ‏:‏ كَانَ النَّبِيُّ صلى الله عليه وسلم مُضْطَجِعًا فِي بَيْتِي، كَاشِفًا عَنْ فَخِذِهِ أَوْ سَاقَيْهِ، فَاسْتَأْذَنَ أَبُو بَكْرٍ رَضِيَ اللَّهُ عَنْهُ، فَأَذِنَ لَهُ كَذَلِكَ، فَتَحَدَّثَ‏.‏ ثُمَّ اسْتَأْذَنَ عُمَرُ رَضِيَ اللَّهُ عَنْهُ، فَأَذِنَ لَهُ كَذَلِكَ، ثُمَّ تَحَدَّثَ‏.‏ ثُمَّ اسْتَأْذَنَ عُثْمَانُ رَضِيَ اللَّهُ عَنْهُ، فَجَلَسَ النَّبِيُّ صلى الله عليه وسلم وَسَوَّى ثِيَابَهُ، قَالَ مُحَمَّدٌ‏:‏ وَلاَ أَقُولُ فِي يَوْمٍ وَاحِدٍ، فَدَخَلَ فَتَحَدَّثَ، فَلَمَّا خَرَجَ قَالَ‏:‏ قُلْتُ‏:‏ يَا رَسُولَ اللهِ، دَخَلَ أَبُو بَكْرٍ فَلَمْ تَهَشَّ وَلَمْ تُبَالِهِ، ثُمَّ دَخَلَ عُمَرُ فَلَمْ تَهَشَّ وَلَمْ تُبَالِهِ، ثُمَّ دَخَلَ عُثْمَانُ فَجَلَسْتَ وَسَوَّيْتَ ثِيَابَكَ‏؟‏ قَالَ‏:‏ أَلاَ أَسْتَحِي مِنْ رَجُلٍ تَسْتَحِي مِنْهُ الْمَلاَئِكَةُ‏؟‏‏.‏