Answer:

You who believe! Do not enter houses other than your own until you have asked permission and greeted their inhabitants. That is better for you, so that hopefully you will pay heed. (Quran, 24:27)

And if you find no one at home do not go in until permission has been granted you. And if you are told to go away then go away. That is purer for you. Allah knows what you do. There is nothing wrong in your entering houses where no one lives and where there is some service for you. Allah knows what you divulge and what you conceal. (Qur’an, 24:28-29)

Answer:

O you who believe! let those you own as slaves, and the (children) among you who have not come of age ask your permission (before they come to your presence), on three occasions: before morning prayer; the while you doff your clothes for the noonday heat; and after the late-night prayer: these are your three times of undress: outside those times it is not wrong for you or for them to move about attending to each other: Thus does Allah make clear the Signs to you: for Allah is full of knowledge and wisdom. (24:58)

Answer:

But when the children among you come of age, let them (also) ask for permission, as do those senior to them (in age): Thus does Allah make clear His Signs to you: for Allah is full of knowledge and wisdom. (24:59)