Washington Post's fatwa on the hijab

I was just reading Jackie Spinner's article in yesterday's Washington Post on the trend among Iraqi girls to wear the hijab so as to avoid standing out in the crowd, and thus becoming targets of kidnappings, shootings, etc... It's a fine article, except for this statement of fact by the author:

Conservative Muslims believe that women should cover their heads to hide their beauty and not tempt the men who see them. Such instructions are spelled out in the Koran, the Islamic holy book.

Spelled out? I don't think so.