Surah 24

Surah 24:31

"And say to the believing women (that) they (should) lower their sight and guard their private parts, and not show their charms, except for what (normally) appears of them. And let them draw their head coverings over their breasts, and not show their charms, except to their husbands, or their fathers, or their husbands’ fathers, or their sons, or their husbands’ sons, or their brothers, or their brothers’ sons, or their sisters’ sons, or their women, or what their right (hands) own, or such men as attend (them who) have no (sexual) desire, or children (who are) not (yet) aware of women’s nakedness. And let them not stamp their feet to make known what they hide of their charms. Turn to God (in repentance) – all (of you) – believers, so that you may prosper."

24.31 – And let them draw their head coverings over their breasts, and not show their charms

The Quran gives instructions about human modesty in a number of verses. These instructions to believing women follow similar instructions to believing men (v. 30). This verse adds that women draw their “head coverings” (khumur, sing. khimār) over their breasts, except in the presence of close male family members.

- from The Quran with Christian Commentary: A Guide to Understanding the Scripture of Islam