The Command from God

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 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, 

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.

Surah An Noor Sign 31 

Quran