O you who acknowledge, do not enter the prophet's homes except if you are invited to a meal, without you forcing such an invitation. But if you are invited, you may enter. When you finish eating, you shall leave, without staying to wait for a hadith. This used to annoy the prophet, and he was shy to tell you. But God does not shy away from the truth. If you ask his wives for something, ask them from behind a barrier. This is purer for your hearts and their hearts. It is not for you to harm God's messenger, nor you should marry his wives after him. This is a gross offence with God.
Translation endnotes
[33:53] See 66:3; 33:38, and 33:32. Verse 4:22 prohibits marrying the exwives of fathers. To keep the privacy of Muhammed's personal life and prevent a possible competition among would-be candidates, the prophet's wives were legally considered to be the mothers of those who acknowledge (33:6).