Ан-Нур 24:58

O you who believe, let those whom your right hands own, of male slaves and female slaves, and those of you who have not reached puberty, from among the free men, and who have not become [sexually] aware of women, ask leave of you three times: at three times [of the day]: before the dawn prayer, and when you put off your garments at noon, and after the night prayer. [These are] three periods of privacy for you (read thalāthu [‘awrātin lakum] with nominative inflection as the predicate of an implied subject followed by a genitive annexation, with the annexed term standing in place thereof [of the predicate], in other words [the implied predicate followed by the annexation is] hiya awqāt, ‘these are times of …’; or read thalātha [‘awrātin lakum] in the accusative, the implication being that awqāta is itself in the accusative as a substitute for the [syntactical] status of what precedes it, in place of which stands the annexed term). It is because clothes are taken off that private parts are revealed during such [periods]. Neither you nor they, namely, slaves and young boys, would be at fault, in entering upon you without asking leave, at other times, that is, after the three times of day [specified]; they frequent you, to provide service, [as] some of you [do] with others (this sentence corroborates the preceding one). So, just as He has clarified what has been mentioned, God clarifies for you the signs, the rulings; and God is Knower, of the affairs of His creatures, Wise, in what He has ordained for them. It is said that the ‘permission’ verse (āyat al-isti’idhān) was abrogated; but it is also said that it was not [abrogated], but that people thought little of neglecting to seek permission [in such situations].