Musnad Ahmad 32:1082

Bahz and Hashim narrated to us, they said: Sulayman ibn al-Mughirah narrated to us, from Thabit, from Anas, who said: When the waiting period of Zaynab ended, the Messenger of Allah (peace be upon him) said to Zayd: "Go and mention me to her." He said: So he set off until he came to her. He said: And she was covering her dough. He said: When I saw her, she became great in my chest, to the point that I could not look at her, because the Messenger of Allah (peace be upon him) had mentioned her. Hashim said: When I knew that the Prophet (peace be upon him) had proposed to her, I turned my back to her and retreated on my heels, and I said: "O Zaynab, rejoice! The Messenger of Allah (peace be upon him) has sent me to mention you." She said: "I will not do anything until I consult my Lord, the Mighty and Majestic." So she stood up and went to her place of prayer, and the Quran was revealed. Then the Messenger of Allah (peace be upon him) came and entered upon her without permission. He said: And I saw us when the Messenger of Allah (peace be upon him) fed us bread and meat upon her (marriage). Hashim said in his narration: I saw us when she was brought in to the Messenger of Allah (peace be upon him), he fed us bread and meat. Then the people left, and some men remained talking in the house after the food. The Messenger of Allah (peace be upon him) went out, and I followed him. He began to go around to the chambers of his wives, greeting them, and they would say: "O Messenger of Allah, how did you find your wife?" He said: I do not know whether I informed him that the people had left, or he was informed. He said: So he set off until he entered the house. I went to enter with him, but he cast the curtain between me and him, and the verse of the Hijab (veiling) was revealed. He said: And he admonished the people with what they were admonished with. Hashim said in his narration: "Do not enter the houses of the Prophet, except when you are permitted for a meal, without waiting for its readiness. But when you are invited, then enter; and when you have eaten, disperse without seeking to remain for conversation. Indeed, that was troubling the Prophet, and he is shy of you, but Allah is not shy of the truth."