Muslim women observe hijab, covering the head and the body "because Allah has told them to do so," said Mary C. Ali, director of The Institute of Islamic Information and Education in Chicago.
In the Quran, it says: "O Prophet, tell your wives and daughters and the believing women to draw their outer garments around them (when they go out or are among men). That is better in order that they may be known [to be Muslims] and not annoyed."
The word "hijab" comes from the Arabic word "hajaba" meaning to hide from view or conceal, Ali said. The goal is modesty but not everyone agrees on the extent of the coverage.
The Quran says women should "draw their veils over their bosoms and not display their beauty except to their husbands."
In an explanation by the Prophet Muhammad, known as a hadith, it says: "When a girl reaches the menstrual age, it is not proper that anything should remain exposed except this and this. He pointed to the face and hands."
The clothing must be loose enough so as not to describe the shape of the woman's body, said Ali, who converted to Islam about 41 years ago and has a degree in Islamic studies and Arabic. It also should not be transparent.
The Quran requires men and women to dress modestly, says Azizah Al-Hibri, a law professor at the University of Richmond in Virginia.
“Depending on the interpretation of certain passages in the Quran, different Muslims cover to different extents," Al-Hibri said in an e-mail. "Some of this is influenced by cultural practices as well." (MORE)