Volume 6, Book 60, Number 317:
Narrated Anas:
When Allah’s Apostle married Zainab bint Jahsh, he made the people eat meat and bread to their
fill (by giving a Walima banquet). Then he went out to the dwelling places of the mothers of the be –
lievers (his wives), as he used to do in the morning of his marriage. He would greet them and invoke
good on them, and they (too) would return his greeting and invoke good on him. When he returned
to his house, he found two men talking to each other; and when he saw them, he went out of his
house again. When those two men saw Allah’s Apostle: going out of his house, they quickly got up
(and departed). I do not remember whether I informed him of their departure, or he was informed
(by somebody else). So he returned, and when he entered the house, he lowered the curtain between
me and him. Then the Verse of Al-Hijab was revealed.