Narrated Anas bin Malik:that he was a boy of ten at the time when the Prophet (ﷺ) emigrated to Medina. He added: I served Allah's Apostle for ten years (the last part of his life time) and I know more than the people about the occasion whereupon the order of Al-Hijab was revealed (to the Prophet). Ubai b n Ka`b used to ask me about it. It was revealed (for the first time) during the marriage of Allah's Messenger (ﷺ) with Zainab bint Jahsh. In the morning, the Prophet (ﷺ) was a bride-groom of her and he Invited the people, who took their meals and went away, but a group of them remained with Allah's Messenger (ﷺ) and they prolonged their stay. Allah's Messenger (ﷺ) got up and went out, and I…

In the Quran

Sahih al-Bukhari 6238