Jami` at-Tirmidhi 3217
Narrated Anas bin Malik:
"I was with the Prophet (ﷺ), and he came to the door of a woman with whom he had consummated marriage, and some people were with her. So, he left to fulfill his need, and was prevented (from her). Then he came back, and some people were still with her. Then he left to fulfill his need and came back and they had gone." He said: "So, I mentioned that to Abu Talhah and he said: 'If it is as you say, something shall surely be revealed concerning this,' and the Verse of Hijab was revealed.
حَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، حَدَّثَنَا أَشْهَلُ بْنُ حَاتِمٍ، قَالَ ابْنُ عَوْنٍ حُدِّثْنَاهُ عَنْ عَمْرِو بْنِ سَعِيدٍ، عَنْ أَنَسِ بْنِ مَالِكٍ، قَالَ كُنْتُ عِنْدَ النَّبِيِّ صلى الله عليه وسلم فَأَتَى بَابَ امْرَأَةٍ عَرَّسَ بِهَا فَإِذَا عِنْدَهَا قَوْمٌ فَانْطَلَقَ فَقَضَى حَاجَتَهُ فَاحْتَبَسَ ثُمَّ رَجَعَ وَعِنْدَهَا قَوْمٌ فَانْطَلَقَ فَقَضَى حَاجَتَهُ فَرَجَعَ وَقَدْ خَرَجُوا قَالَ فَدَخَلَ وَأَرْخَى بَيْنِي وَبَيْنَهُ سِتْرًا قَالَ فَذَكَرْتُهُ لأَبِي طَلْحَةَ قَالَ فَقَالَ لَئِنْ كَانَ كَمَا تَقُولُ لَيَنْزِلَنَّ فِي هَذَا شَيْءٌ ‏.‏ فَنَزَلَتْ آيَةُ الْحِجَابِ ‏.‏ هَذَا حَدِيثٌ حَسَنٌ غَرِيبٌ مِنْ هَذَا الْوَجْهِ ‏.‏