O you who believe! let those whom your right hands possess and those of you who have not attained to puberty ask permission of you three times; before the morning prayer, and when you put off your clothes at midday in summer, and after the prayer of the nightfall; these are three times of privacy for you; neither is it a sin for you nor for them besides these, some of you must go round about (waiting) upon others; thus does Allah make clear to you the communications, and Allah is Knowing, Wise.

And (as for) those of your women who have despaired of menstruation, if you have a doubt, their prescribed time shall be three months, and of those too who have not had their courses; and (as for) the pregnant women, their prescribed time is that they lay down their burden; and whoever is careful of (his duty to) Allah He will make easy for him his affair.