“And they shall not display their beauty and ornaments, except what is apparent of it. And they should draw their khemaars over their bosoms, and shall not relax this code in the presence of other than…” (Qur’an, Surah an-Nur, 24:31)
The term ‘Khemaar` in Arabic means whatever clothes which may cover the head, like scarf. The context of the Ayah clearly shows that head covering is an issue out of discussion, perhaps because it has already been mentioned in the previous Scriptures.
The Ayah is asking for something more, i.e. to make the scarf or whatever women are covering their hair with, long enough to be able to draw it over their bosoms and necks.
Adapted from: “Hijab, A Divine Value” by: “Sheikh Mansour Leghaei”