Al-Quran- Sura No(24), Ayat(58)

O ye who believe! Let your slaves, and those of you who have not come to puberty, ask leave of you at three times before they come into your presence: Before the prayer of dawn, and when ye lay aside your raiment for the heat of noon, and after the prayer of night. Three times of privacy for you. It is no sin for them or for you at other times, when some of you go round attendant upon others if they come into your presence without leave. Thus Allah maketh clear the revelations for you. Allah is Knower, Wise.