Narrated Anas:

A banquet of bread and meat was held on the occasion of the marriage of the Prophet to Zainab bint Jahsh. I was sent to invite the people (to the banquet), and so the people started coming (in groups),
They would eat and then leave. Another batch would come, eat and leave. So I kept on inviting the people till I found nobody to invite. Then I said, "O Allah's Prophet! I do not find anybody to invite." He said, "Carry away the remaining food." Then a batch of three persons stayed in the house chatting. The Prophet left and went towards the dwelling place of Aisha and said, "Peace and Allah's Mercy be on you, O the people of the house!" She replied, "Peace and the mercy of Allah be on you too. How did you find your wife? May Allah bless you. Then he went to the dwelling places of all his other wives and said to them the same as he said to Aisha and they said to him the same as Aisha had said to him. Then the Prophet returned and found a group of three persons still in the house chatting. The Prophet was a very shy person, so he went out (for the second time) and went towards the dwelling place of 'Aisha. I do not remember whether I informed him that the people have gone away. So he returned and as soon as he entered the gate, he drew the curtain between me and him, and then the Verse of Al-Hijab was revealed.

حَدَّثَنَا أَبُو مَعْمَرٍ، حَدَّثَنَا عَبْدُ الْوَارِثِ، حَدَّثَنَا عَبْدُ الْعَزِيزِ بْنُ صُهَيْبٍ، عَنْ أَنَسٍ ـ رضى الله عنه ـ قَالَ بُنِيَ عَلَى النَّبِيِّ ﷺ بِزَيْنَبَ ابْنَةِ جَحْشٍ بِخُبْزٍ وَلَحْمٍ فَأُرْسِلْتُ عَلَى الطَّعَامِ دَاعِيًا فَيَجِيءُ قَوْمٌ فَيَأْكُلُونَ وَيَخْرُجُونَ، ثُمَّ يَجِيءُ قَوْمٌ فَيَأْكُلُونَ وَيَخْرُجُونَ، فَدَعَوْتُ حَتَّى مَا أَجِدُ أَحَدًا أَدْعُو فَقُلْتُ يَا نَبِيَّ اللَّهِ مَا أَجِدُ أَحَدًا أَدْعُوهُ قَالَ ارْفَعُوا طَعَامَكُمْ، وَبَقِيَ ثَلاَثَةُ رَهْطٍ يَتَحَدَّثُونَ فِي الْبَيْتِ، فَخَرَجَ النَّبِيُّ ﷺ فَانْطَلَقَ إِلَى حُجْرَةِ عَائِشَةَ فَقَالَ " السَّلاَمُ عَلَيْكُمْ أَهْلَ الْبَيْتِ وَرَحْمَةُ اللَّهِ ". فَقَالَتْ وَعَلَيْكَ السَّلاَمُ وَرَحْمَةُ اللَّهِ، كَيْفَ وَجَدْتَ أَهْلَكَ بَارَكَ اللَّهُ لَكَ فَتَقَرَّى حُجَرَ نِسَائِهِ كُلِّهِنَّ، يَقُولُ لَهُنَّ كَمَا يَقُولُ لِعَائِشَةَ، وَيَقُلْنَ لَهُ كَمَا قَالَتْ عَائِشَةُ، ثُمَّ رَجَعَ النَّبِيُّ ﷺ فَإِذَا ثَلاَثَةُ رَهْطٍ فِي الْبَيْتِ يَتَحَدَّثُونَ، وَكَانَ النَّبِيُّ ﷺ شَدِيدَ الْحَيَاءِ، فَخَرَجَ مُنْطَلِقًا نَحْوَ حُجْرَةِ عَائِشَةَ فَمَا أَدْرِي آخْبَرْتُهُ أَوْ أُخْبِرَ أَنَّ الْقَوْمَ خَرَجُوا، فَرَجَعَ حَتَّى إِذَا وَضَعَ رِجْلَهُ فِي أُسْكُفَّةِ الْبَابِ دَاخِلَةً وَأُخْرَى خَارِجَةً أَرْخَى السِّتْرَ بَيْنِي وَبَيْنَهُ، وَأُنْزِلَتْ آيَةُ الْحِجَابِ.