In the Quran, policies for women's dress are mentioned in several passages; we include two of the most oft-cited here, using translations from the BBC:
Chapter 33, Verse 59: O Prophet! Tell thy wives and daughters, and the believing women, that they should cast their outer garments over their persons: that is most convenient, that they should be known (as such) and not molested.
Chapter 24, Verses 30-31: Say to the believing men that they should lower their gaze and guard their modesty: that will make for greater purity for them: And Allah is well acquainted with all they do. And say to the believing women that they should lower their gaze and guard their modesty; that they should not display their beauty and ornaments except what must ordinarily appear thereof.
There is no doubt among Muslim scholars that the faithful, both male and female, must maintain modest dress. Men should be covered between the navel and the knee, and in another passage, they are directed not to wear silk. But scholars differ over female dress because of the words "except what must ordinarily appear thereof." Some believe that the hands and the face must ordinarily appear in the course of a woman going about her day, and that a full face veil isn't required. After all, if Muhammad meant for women to be completely covered, then why would men be instructed in the very same passage to avert their gaze in the name of modesty? If a woman was fully covered, there would be no need for a man to look away. To these scholars, hijab, or a head covering, is necessary, but a niqab or a burqa is not [source: BBC].
A minority of scholars, though, believe that since full covering is possible, thanks to the burqa and the niqab, then faithful women should cover their face and their hands completely. Full covering, including of the face, is a sign of extreme piety. Regardless of which way women choose to interpret the passage, hijab is a religious obligation and will fulfill the first passage, in which women are called upon to be recognized as Muslims in public.
It's worth noting that another passage in the Quran includes a list of people in whose presence a woman may go unveiled. These include husbands, brothers, fathers, slaves and other Muslim women.
On the next page, we'll consider some reasons why women wear the full veil when some scholars say it's unnecessary.