Surah al-Ahzab verse 59 reads:
O Prophet! Say to your wives and your daughters and the women of the faithful to draw their outergarments (jilbabs) close around them; that is better that they will be recognized and not annoyed. And God is ever Forgiving, Gentle.
Surah an-Nur verse 31 reads:
And say to the faithful women to lower their gazes, and to guard their private parts, and not to display their beauty except what is apparent of it, and to extend their headcoverings (khimars) to cover their bosoms, and not to display their beauty except to their husbands, or their fathers, or their husband's fathers, or their sons, or their husband's sons, or their brothers, or their brothers' sons, or their sisters' sons, or their womenfolk, or what their right hands rule (slaves), or the followers from the men who do not feel sexual desire, or the small children to whom the nakedness of women is not apparent, and not to strike their feet (on the ground) so as to make known what they hide of their adornments. And turn in repentance to God together, O you the faithful, in order that you are successful.
*U may also link to this site :http://www.muhajabah.com/dresslikethat.htm
Wassalam J