Purdah is an Indian word which is sometimes translated as “seclusion”. It refers to the practice of some Muslim women of staying at home so as to avoid mixing with men, other than the husband, family members and close friends.
The practice is traced to a verse of the Qur’an which is directed specifically to the Prophet’s wives:
“O wives of the Prophet! You are not like any of the (other) women: If you do fear (Allah) be not too complaisant in speech, lest one in whose heart is a disease should be moved with desire: but speak in a way (that is) just. And stay quietly in your houses, and make not a dazzling display, like that of the former Times of ignorance…” (Qur’an 33:32-33)
The wives of the Prophet were in a unique situation: since
- he was a prophet and
- he was also Head of State.
In their capacity as wives of the Prophet they were given the title “Mothers of the Believers”, and they had responsibilities of teaching Islam to other women and of answering questions about Islam from people in general. The Prophet (r) said of his wife Aisha: “You can get that half your religion from this rosy-cheeked girl”. Therefore the wives were directed to be careful in the way they conversed with other men so as not to awaken unlawful desires.
In their capacity as wives of a Head of State, they might also be tempted to show off. The verses direct them to live modestly, not to go out unnecessarily and not to make a parade of beauty or adornment as was done by women in the period before Islam, called “the Times of Ignorance”.
Nevertheless, the Prophet’s wives were not forbidden to go out. When one of his wives asked him, he affirmed “Women are allowed to go out for their needs”. One does not have to be a genius to comprehend that human needs are vast in substance. Hence, it would not be justifiable on the basis of this Hadith to only permit women to leave home to go to market, visit their family and see the doctor. Furthermore, women in the Prophet’s time saw fit to work, attend gatherings, pray in the mosques, travel in caravanserais and on other long journeys including the Hijrah from Makkah to Madinah, and even fight battles alongside men – all outside their homes. The Caliph Umar appointed a woman, Shaffa bint Abdullah bin Abdush-Shams, as chief administrator of the market place, and the Prophet (r) even prayed for a woman, at her request, to be one of those of his Ummah who would eventually embark on great sea expeditions.
Despite all this, many held the view that confining oneself to one’s house would constitute greater piety for a woman, and later generations of Muslims in some parts of the world made seclusion into a widespread practice for nearly all women, or at least for the wealthy classes.
In other places however women have continued to have economic and social roles outside the home. In modern times, Muslim girls go out to schools and universities, in accordance with the Prophet’s (r) saying: “The search for knowledge is a compulsory duty for every Muslim, male and female”. Muslim women also have resumed the role they used to play in the early days of Islam in teaching, nursing, medicine, social work and other necessary services to the community, particularly services to other women and children.
If any woman has the desire and the means to practice seclusion in emulation of the Prophet’s wives, she is free to do so. However, the generality of Muslim women with the consent of their husbands, can and do go out according to their individual needs. However, they are required to dress modestly in accordance with the requirements of Hijab and not to mix unnecessarily with men. These practices, as earlier mentioned, are designed to help preserve morality in the society and to protect family life.
Apart from the issue of dress, both men and women are urged in the Qur’an (24:30-31) to lower their gaze and avoid looking at the opposite sex. They should avoid flirtatious manners and ways of talking (Q33:32-33). They should also avoid intermingling with the opposite sex in such way that their bodies come in contact, for example in university classrooms, buses and other public places.
However, provided these conditions are observed and there is no immoral intent, it is not forbidden for men and women to be present at the same occasion. 
If Islam had prescribed strict segregation of the sexes, it would have surely been prescribed for the great gathering of Hajj. Instead both sexes perform the Hajj together and it is even prohibited for a woman to cover her face during Hajj.
 Quran 33:6
 Assakhawi, Abdurahman. Almaqasid alhasana. P. 321. Dar alkitab alaraby. Sakhawi said the hadith is fabricated. Shaukani, Muhammad bn Ali, Alfawaid almajmu’a fil ahadith almaudu’a no: 139. Almaktab alislami, Bdeirut.1407AH
 Mubarakphury, Safiyu rahman Arrahiq almakhtum p. 26
 Narrated by Aisha in Sahih al-Bukhari, vol.6, hadith no.318 in Alim 6.0
 Muslim women in the public space p.3
 Tabarani, Abulqasim Sulaiman bn Ahmad. Mujamul awsat:9 Dar alharamain 1415, Egypt. Ibn Majah 224, Musnad Abiyala:2837. Musnad Albazar: 7478.
 Mula Ali alqari, Sharh Musnad Abi Hanifa. V1p537.
 See al-Qaradawi: The Lawful and the Prohibited in Islam, pp. 164-168.