وَقُلْ لِّلْمُؤْمِنٰتِ يَغْضُضْنَ مِنْ اَبْصَارِهِنَّ وَيَحْفَظْنَ فُرُوْجَهُنَّ وَلَا يُبْدِيْنَ زِيْنَتَهُنَّ اِلَّا مَا ظَهَرَ مِنْهَا وَلْيَضْرِبْنَ بِخُمُرِهِنَّ عَلٰى جُيُوْبِهِنَّۖ وَلَا يُبْدِيْنَ زِيْنَتَهُنَّ اِلَّا لِبُعُوْلَتِهِنَّ اَوْ اٰبَاۤىِٕهِنَّ اَوْ اٰبَاۤءِ بُعُوْلَتِهِنَّ اَوْ اَبْنَاۤىِٕهِنَّ اَوْ اَبْنَاۤءِ بُعُوْلَتِهِنَّ اَوْ اِخْوَانِهِنَّ اَوْ بَنِيْٓ اِخْوَانِهِنَّ اَوْ بَنِيْٓ اَخَوٰتِهِنَّ اَوْ نِسَاۤىِٕهِنَّ اَوْ مَا مَلَكَتْ اَيْمَانُهُنَّ اَوِ التَّابِعِيْنَ غَيْرِ اُولِى الْاِرْبَةِ مِنَ الرِّجَالِ اَوِ الطِّفْلِ الَّذِيْنَ لَمْ يَظْهَرُوْا عَلٰى عَوْرٰتِ النِّسَاۤءِ ۖوَلَا يَضْرِبْنَ بِاَرْجُلِهِنَّ لِيُعْلَمَ مَا يُخْفِيْنَ مِنْ زِيْنَتِهِنَّۗ وَتُوْبُوْٓا اِلَى اللّٰهِ جَمِيْعًا اَيُّهَ الْمُؤْمِنُوْنَ لَعَلَّكُمْ تُفْلِحُوْنَ ( النور: ٣١ )
Wa qul lilmu'minaati yaghdudna min absaarihinna wa yahfazna furoojahunna wa laa yubdeena zeenatahunna illaa maa zahara minhaa walyadribna bikhumurihinna 'alaa juyoobihinna wa laa yubdeena zeenatahunna illaa libu'oolatihinna aw aabaaa'i hinna aw aabaaa'i bu'oolati hinna aw abnaaa'ihinaa aw abnaaa'i bu'oolatihinnna aw ikhwaanihinnna aw baneee ikhwaanihinna aw banee akhawaatihinna aw nisaaa'i hinna aw maa malakat aimaanuhunna awit taabi'eena ghairi ilil irbati minar rijaali awit tiflillazeena lam yazharoo 'alaa 'awraatin nisaaa'i wala yadribnna bi arjulihinna min zeenatihinn; wa toobooo ilallaahi jammee'an aiyuhal mu'minoona la'allakum tuflihoon (an-Nūr 24:31)
And tell the believing women to reduce [some] of their vision and guard their private parts and not expose their adornment except that which [necessarily] appears thereof and to wrap [a portion of] their headcovers over their chests and not expose their adornment [i.e., beauty] except to their husbands, their fathers, their husbands' fathers, their sons, their husbands' sons, their brothers, their brothers' sons, their sisters' sons, their women, that which their right hands possess [i.e., slaves], or those male attendants having no physical desire, or children who are not yet aware of the private aspects of women. And let them not stamp their feet to make known what they conceal of their adornment. And turn to Allah in repentance, all of you, O believers, that you might succeed. (An-Nur  : 31)
1 Mufti Taqi Usmani
And tell the believing women that they must lower their gazes and guard their private parts, and must not expose their adornment, except that which appears thereof, and must wrap their bosoms with their shawls, and must not expose their adornment, except to their husbands or their fathers or the fathers of their husbands, or to their sons or the sons of their husbands, or to their brothers or the sons of their brothers or the sons of their sisters, or to their women, or to those owned by their right hands, or male attendants having no (sexual) urge, or to the children who are not yet conscious of the shames of women. And let them not stamp their feet in a way that the adornment they conceal is known. And repent to Allah O believers, all of you, so that you may achieve success.