I think that most of the Muslims and non Muslims think hijab is a religious obligation of Islam to Muslim women.
We informally call to all the veils, except the Niqab and the Burqa, Hijab.
Islam says that both men and women should dress with modesty. These are words from God in the Holy Quran:
[24.30] قُلْ لِلْمُؤْمِنِينَ يَغُضُّوا مِنْ أَبْصَارِهِمْ وَيَحْفَظُوا فُرُوجَهُمْ ذَلِكَ أَزْكَى لَهُمْ إِنَّ اللَّهَ خَبِيرٌ بِمَا يَصْنَعُونَ
[24.30] Say to the believing men that they should lower their gaze and guard their modesty: that will make for greater purity for them: And Allah is well acquainted with all that they do.
[24.31] وَقُلْ لِلْمُؤْمِنَاتِ يَغْضُضْنَ مِنْ أَبْصَارِهِنَّ وَيَحْفَظْنَ فُرُوجَهُنَّ وَلا يُبْدِينَ زِينَتَهُنَّ إِلا مَا ظَهَرَ مِنْهَا وَلْيَضْرِبْنَ بِخُمُرِهِنَّ عَلَى جُيُوبِهِنَّ وَلا يُبْدِينَ زِينَتَهُنَّ إِلا لِبُعُولَتِهِنَّ أَوْ آبَائِهِنَّ أَوْ آبَاءِ بُعُولَتِهِنَّ أَوْ أَبْنَائِهِنَّ أَوْ أَبْنَاءِ بُعُولَتِهِنَّ أَوْ إِخْوَانِهِنَّ أَوْ بَنِي إِخْوَانِهِنَّ أَوْ بَنِي أَخَوَاتِهِنَّ أَوْ نِسَائِهِنَّ أَوْ مَا مَلَكَتْ أَيْمَانُهُنَّ أَوِ التَّابِعِينَ غَيْرِ أُولِي الإرْبَةِ مِنَ الرِّجَالِ أَوِ الطِّفْلِ الَّذِينَ لَمْ يَظْهَرُوا عَلَى عَوْرَاتِ النِّسَاءِ وَلا يَضْرِبْنَ بِأَرْجُلِهِنَّ لِيُعْلَمَ مَا يُخْفِينَ مِنْ زِينَتِهِنَّ وَتُوبُوا إِلَى اللَّهِ جَمِيعًا أَيُّهَا الْمُؤْمِنُونَ لَعَلَّكُمْ تُفْلِحُونَ
[24.31] And say to the believing women that they should lower their gaze and guard their modesty; that they should not display their beauty and ornaments except what (must ordinarily) appear thereof; that they should draw their veils over their bosoms and not display their beauty except to their husbands, their fathers, their husband’s fathers, their sons, their husbands’ sons, their brothers or their brothers’ sons, or their sisters’ sons, or their women, or the slaves whom their right hands possess, or male servants free of physical needs, or small children who have no sense of the shame of sex; and that they should not strike their feet in order to draw attention to their hidden ornaments…
As you see about clothing, Islam doesn’t really say how to dress. Only that you should guard your modesty, cover your breasts and yours sexual attributes.
So everyone specify that Muslims should not display between the belly until the knees (special if you’re a women) and your breasts.
Why cover the hair? Is it a sexual attribute? Since when you feel attracted by someone’s hair? If yes I recommend that you should go to the medic.
However the main Quranic argument is on the Surah Al Ahzaab:
[33.59] يَا أَيُّهَا النَّبِيُّ قُلْ لأزْوَاجِكَ وَبَنَاتِكَ وَنِسَاءِ الْمُؤْمِنِينَ يُدْنِينَ عَلَيْهِنَّ مِنْ جَلابِيبِهِنَّ ذَلِكَ أَدْنَى أَنْ يُعْرَفْنَ فَلا يُؤْذَيْنَ وَكَانَ اللَّهُ غَفُورًا رَحِيمًا
[33.59] O Prophet! Tell thy wives and daughters, and the believing women, that they should cast their outer garments over their persons (when abroad): that is most convenient, that they should be known (as such) and not molested. And Allah is Oft-Forgiving, Most Merciful.
In order to understand this verse you need some background study.
The IRFI – Islamic Research Foundation International, Inc. has in it’s website this issue explained:
“According to the Quran, the reason why Muslim women should wear an outer garment when going out of their homes is that they may be recognized as “Believing” women and differentiated from streetwalkers for whom sexual harassment is an occupational hazard. The purpose of this verse was not to confine women to their homes, but to make it safe for them to go about their daily business without attracting unsavory attention.”
“The Quran does not suggest that women should be veiled or they should be kept apart from the world of men. On the contrary, the Quran is insistent on the full participation of women in society and in the religious practices.
Morality of the self and cleanliness of conscience are far better than the morality of the purdah. No goodness can come from pretence. Imposing the veil on women is the ultimate proof that men suspect their mothers, daughters, wives and sisters of being potential traitors to them. How can Muslim men meet non-Muslim women who are not veiled and treat them respectfully, but not accord the same respectful treatment to Muslim women?
To wear the Hijaab is certainly NOT an Islamic obligatory on women. It is an innovation (Bid’ah) of men suffering from a piety complex who are so weak spiritually that they just cannot trust themselves!”
Older women as they are no longer a source of sexual attraction they don’t have to take specially attention to their cloth when outside. This is according to the Holy Quran:
[24.60] وَالْقَوَاعِدُ مِنَ النِّسَاءِ اللاتِي لا يَرْجُونَ نِكَاحًا فَلَيْسَ عَلَيْهِنَّ جُنَاحٌ أَنْ يَضَعْنَ ثِيَابَهُنَّ غَيْرَ مُتَبَرِّجَاتٍ بِزِينَةٍ وَأَنْ يَسْتَعْفِفْنَ خَيْرٌ لَهُنَّ وَاللَّهُ سَمِيعٌ عَلِيمٌ
[24.06] Such elderly women as are past the prospect of marriage, – there is no blame on them if they lay aside their (outer) garments, provided they make not a wanton display of their beauty: but it is best for them to be modest: and Allah is One Who sees and knows all things.
IRFI: “It is part of the growing feeling on the part of Muslim men and women that they no longer wish to identify with the West, and that reaffirmation of their identity as Muslims requires the kind of visible sign that adoption of conservative clothing implies.
For these women the issue is not that they have to dress conservatively, but that they choose to.”
I would like to say that I personally like women who wear the Hijab but that doesn’t discourage me to tell Muslims sister that they only have to wear hijab if they want to.
Note that in some countries using the Hijab may draw more eye attention to you but it allow that other people including Muslims know that you are Muslim sister 😉
So remember: Hijab is not obligatory, MODEST dress is.