A. Yusuf Ali:Translation:
O you who believe! 3033 Let those whom your right
hands 3034 possess, and the (children) among you
who have not come of age 3035 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 latenight prayer: these are your three times 3036 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.

Muhammad Asad:Translation:
O YOU who have attained to faith! 77 At three times [of day], let [even] those whom you rightfully possess, 78 as well as those from among you who have not yet attained to puberty, 79 ask leave of you [before intruding upon your privacy]: before the prayer of daybreak, and whenever you lay aside your garments in the middle of the day, and after the prayer of nightfall: 80 the three occasions on which your nakedness is likely to be bared. 81 Beyond these [occasions], neither you nor they will incur any sin if they move [freely] about you, attending to [the needs of] one another. In this way God makes clear unto you His messages: for God is all-knowing, wise!
3033 We now come to rule of decorum within the family circle in refined society. Servants and children have rather more freedom of access, as they come and go at all hours, and there is less ceremony with them. But even in their case there are limitations. During the night, before morning prayer, i.e., before dawn, they must discreetly ask for permission before they enter, partly because they must not unnecessarily disturb people asleep, and partly because the people are then undressed. The same applies to the time for the midday siesta, and again to the time after night prayers, when people usually undress and turn in to sleep. For grown-ups the rule is stricter: they must ask permission to come in at all times (24:59).
3034 This would mean slaves in a regime of slavery. But the principle applies to all personal servants, who have to render personal service to their masters or mistresses by day and by night.
3035 I have translated "come of age" euphemistically for "attain the age of puberty".
3036 It is mark of refinement for ladies and gentlemen not to be slipshod or vulgarly familiar, in dress, manners, or speech; and Islam aims at making every Muslim man or woman, however humble in station, a refined gentleman or lady, so that he or she can climb the ladder of spiritual development with humble confidence in Allah, and with the cooperation of his brothers and sisters in Islam. The principles here laid down apply, if they are interpreted with due elasticity, even if social and domestic habits change, with changes in climate or in racial and personal habits. Punctilious self-respect and respect for others, in small things as well as great, are the keynotes in the simple rules of etiquette.