Surah an-Nur ayah 31 says:
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 (jaybs), 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 Allah together, O you the faithful, in order that you are successful.
Surah al-Ahzab ayah 59 says:
O Prophet! Say to your wives and your daughters and the women of the faithful to draw their outergarments (jilbabs) close around themselves; that is better that they will be recognized and not annoyed. And God is ever Forgiving, Gentle.
"Wahai Nabi, suruhlah isteri-isterimu dan anak-anak perempuanmu serta perempuan-perempuan yang beriman, supaya melabuhkan pakaiannya bagi menutup seluruh tubuhnya (semasa mereka keluar); cara yang demikian lebih sesuai untuk mereka dikenal (sebagai perempuan yang baik-baik) maka dengan itu mereka tidak diganggu. Dan (ingatlah) Allah adalah Maha Pengampun, lagi Maha Mengasihani." (Surah Al-Ahzab: AYAT 59)