Anas bin Malik reported,

I am the most knowledgeable of people regarding this verse, the verse of the hijab. When Zaynab bint Jahsh رضي الله عنها was brought as a bride to the Messenger of Allah ﷺ, she was with him in the house. He prepared food and invited the people. They sat talking, so the Prophet ﷺ would go out and then return while they were still sitting and talking. Then Allah the Exalted revealed,"Believers, do not enter the houses of the Prophet unless permission is granted you for a meal, and even then not so early as to wait for it to be prepared," up to His words, "from behind a screen" [Ahzab 33:53].So the screen was put up and the people rose to leave.

Bukhari 4792

Sahih

حدثنا سليمان بن حرب حدثنا حماد بن زيد عن أيوب عن أبي قلابة قال

أنس بن مالك

أنا أعلم الناس بهذه الآية آية الحجاب لما أهديت زينب بنت جحش رضي الله عنها إلى رسول الله ﷺ كانت معه في البيت صنع طعاما ودعا القوم فقعدوا يتحدثون فجعل النبي ﷺ يخرج ثم يرجع وهم قعود يتحدثون فأنزل الله تعالى {يا أيها الذين آمنوا لا تدخلوا بيوت النبي إلا أن يؤذن لكم إلى طعام غير ناظرين إناه} إلى قوله {من وراء حجاب} فضرب الحجاب وقام القوم

البخاري 4792صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Bukhari
Book
Tafsir
Chapter
His saying, "Do not enter the houses of the Prophet except when you are permitted for a meal, without awaiting its readiness. But when you are invited, then enter; and when you have eaten, disperse and do not seek to remain for conversation. Indeed, that was troubling the Prophet, and he is shy of you, but Allah is not shy of the truth. And when you ask them for something, ask them from behind a partition. That is purer for your hearts and their hearts. And it is not for you to trouble the Messenger of Allah or to marry his wives after him ever. Indeed, that would be, in the sight of Allah, an enormity."
Numbering
Darussalam 4792
Bukhari 4792