Summary: O Prophet! Tell your wives and your daughters and the women of the faithful to draw closely over themselves their jilba-b...
When we look at the Holy Qur’an we find that it has addressed the issue of hijab in about ten verses and in none of these verses Allah (swt) introduce hijab as a new command. It is not a new command. Islam did not introduce hijab for the first time; rather, Islam tries to remind us of that which has always existed and ensure that we understand and practise it in its proper way.
For example, Prophet Muhammad (s) was asked by Allah (swt) to tell ladies that they should keep their covering, or jilbab, close to themselves, so that it covers them properly:
يَا أَيُّهَا النَّبِيُّ قُل لِّأَزْوَاجِكَ وَبَنَاتِكَ وَنِسَاء الْمُؤْمِنِينَ يُدْنِينَ عَلَيْهِنَّ مِن جَلَابِيبِهِنَّ ذَلِكَ أَدْنَى أَن يُعْرَفْنَ فَلَا يُؤْذَيْنَ وَكَانَ اللَّهُ غَفُورًا رَّحِيمًا
O Prophet! Tell your wives and your daughters and the women of the faithful to draw closely over themselves their jilba-b... {1}
Allah (swt) did not say that they should wear a jilba-b because this was a known and understood idea at the time, but they did not know how to practise it correctly so sometimes they wore it so loosely that the parts of the body supposed to be covered were visible.
Through the Holy Prophet (s), Allah (swt) asked them to keep their jilba-b close to their bodies so that it suitably covered and protected them. Allah (swt) also told the Holy Prophet (s) to ask the believing men to be cautious about their approach in looking at women because this is another aspect of a woman’s protection.
Thus, part of the protection of her beauty derives from the lady wearing proper hijab and part of the protection comes from Allah (swt) asking men to respect a lady by not having bad intentions when looking at her and by not looking at the parts of her body that are not to be seen. To protect the beauty of a lady, Allah (swt) says that men of faith, principles, and high values should be careful about the way in which they look at her, all of which is done out of a sense of care, respect and honour for a lady.
Footnote:
1) 33:59
Source:http://alhassanain.org/english/?com=content&id=1106&search=Hijab