O you who believe! Let those whom your right hands possess (slaves), and the children amongst you who have not reached puberty, ask leave of you on three occasions (before coming into your presence) - before the prayer of dawn, and when you put off your clothes because of the heat at noon, and after the evening prayer - three occasions of privacy (or undress) for you. It is no sin on either you or them at other times, to go about attending to each other (without express permission). Thus does Allah explain to you His revelations, for Allah is Knower, Wise.