Is not the basic purpose of wearing the Hijāb not to arouse males? Should not then males be asked to control themselves and not stare at women?
I am afraid this is an incorrect inference. ‘Not to arouse males’, is certainly not the purpose of the Hijāb. Nowhere does the Qur’ān say so. On the contrary, the main purpose of the Hijāb, as stated by the Qur’ān, is to purify the soul of the person who is wearing it. The Qur’ān explicitly states that the basic purpose of Islamic directives is to achieve inner purification:
It is He who has sent among the unlettered a Messenger from amongst themselves who rehearses upon them His verses and purifies them and for this he instructs them in law and in wisdom. (62:2)
It is only a purified soul who will enter Paradise in the Hereafter. So one must strive one’s utmost to try to cleanse oneself from things which pollute the soul. Not wearing the Hijāb, according the Qur’ān, is a hindrance in this purification for women. Consequently, during the Hijāb verse of Sūrah Nūr, this objective is mentioned in the following words:
That is purer for them. (24:30)