I am the most knowledgeable of people about this verse, the verse of the screen. When Zaynab bint Jahsh was given in marriage to the Messenger of Allah ﷺ, she was with him in the house. He prepared food and invited the people, and they sat talking. The Prophet ﷺ would go out and then come back while they were still sitting and talking.Then Allah the Exalted revealed "You who believe, do not enter the houses of the Prophet unless permission is given to you for a meal, without waiting for it to be prepared" up to His words "from behind a screen" [Ahzab 33:53]. So the screen was put in place, and the people rose and left.
أنا أعلم الناس بهذه الآية آية الحجاب لما أهديت زينب بنت جحش 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: {يأيها الذين ءامنوا لا تدخلوا بيوت النبي إلا أن يؤذن لكم إلى طعام غير نظرين إناه} إلى قوله {من وراء حجاب} فضرب الحجاب، وقام القوم.
Bukhari narrated it in the tafsir (4792) from Sulayman bin Harb, who said, Hammad bin Zayd narrated to us, from Ayub, from Abu Qilaba, who said, Anas bin Malik mentioned it.