Holy Qur’an 33:54
O ye who believe! enter not the houses of the Prophet unless leave is granted to you for a meal without waiting for its appointed time. But enter when you are invited, and when you have finished eating, disperse, without seeking to engage in talk. That causes inconvenience to the Prophet, and he feels shy of asking you to leave. But Allah is not shy of saying what is true. And when you ask them (the wives of the Prophet) for anything, ask them from behind a curtain. That is purer for your hearts and their hearts. And it behoves you not to cause inconvenience to the Messenger of Allah, nor that you should ever marry his wives after him. Indeed that would be an enormity in the sight of Allah.
Translation: Maulawi Sher Ali (Ahmadiyya Muslim Jamaat)