Salam bros and sis! :D
This is a response to this question. Bismillah. :)
Here are some rationale behind the obligatory Hijab and covering Aurah:
- Self-respect. What does it mean to respect oneself? It means to give the body its right and to safeguard his/her pride and dignity. e.g. One who have self-respect would sleep on time, so that the body would have enough rest and have strong immunity against sicknesses. When a woman covers her aurah properly, she is actually safeguarding herself from potential harm - uncomfortable and unwanted ogling from perverted men, arousing men sexually by her appeal which is the main reason for many rape cases, etc. Covering Aurah properly = Self-respect.
- Modesty. By definition, the word means: 1. Freedom from vanity and boastfulness. 2. regard for decency of behaviour, speech, dress etc. 3. Simplicity/Moderation. Need I elaborate more? :D
- Brain and personality over looks. You want people to judge you solely by your internal, and not external beauty.
Visit this page for the daleels: http://www.muhajabah.com/dresslikethat.htm
Wallahua’lam. :D