Khalwa.

Retreat

In Sufism

Sufism

Sufism or ' is defined by its adherents as the inner, mystical dimension of Islam. A practitioner of this tradition is generally known as a '...

, a solitary retreat, traditionally for 40 days (see "chella

Chilla-nashini

Chilla-nashini is a spiritual practice of penance and solitude, known mostly in Indian and Persian traditions. In this ritual a mendicant or ascetic attempts to remain seated in a circle practicing meditation techniques without food for 40 days and nights. The word 'chilla' is adopted from the...

"), during which a disciple does extensive spiritual exercises under the direction of a sufi master.

A Sufi murid

Murid

Murid is a Sufi term meaning 'committed one' from the root meaning "willpower" or "self-esteem". It refers to a person who is committed to a Murshid in a Tariqa of Sufism. Also known as a Salik , a murid is an initiate into the mystic philosophy of Sufism. When the Talib makes a pledge to a...

 will enter khalwa under the direction of a shaykh

Shaykh of Sufism

A Shaykh , , of Sufism is a Sufi who is authorized to teach, initiate and guide aspiring dervishes. The shaykh is vital to the path of the novice sufi, for the shaykh has himself travelled the path of mysticism...

 for a given period, sometimes for as long as 40 days, emerging only to pray

Salat

Salah is the practice of formal prayer in Islam. Its importance for Muslims is indicated by its status as one of the Five Pillars of Sunni Islam, of the Ten Practices of the Religion of Twelver Islam and of the 7 pillars of Musta'lī Ismailis...

 and, usually, to discuss dreams, visions and the like with the shaykh. Once a major element of Sufi practice, khalwa has become less frequent in recent years.

Other uses

• A religious school is known as "a khalwa" in the Sudanese
  Sudan
  Sudan , officially the Republic of the Sudan , is a country in North Africa, sometimes considered part of the Middle East politically. It is bordered by Egypt to the north, the Red Sea to the northeast, Eritrea and Ethiopia to the east, South Sudan to the south, the Central African Republic to the...
  
   dialect of Arabic. This reflects the former dominance of Sufism in the Sudan.
• The Khalwati order (Halveti) of Sufism derives its name from the term "khalwa".

Other contexts

• The prayer-houses of the Druze
  Druze
  The Druze are an esoteric, monotheistic religious community, found primarily in Syria, Lebanon, Israel, and Jordan, which emerged during the 11th century from Ismailism. The Druze have an eclectic set of beliefs that incorporate several elements from Abrahamic religions, Gnosticism, Neoplatonism...
  
   are called khalwaat and are used in place of mosque
  Mosque
  A mosque is a place of worship for followers of Islam. The word is likely to have entered the English language through French , from Portuguese , from Spanish , and from Berber , ultimately originating in — . The Arabic word masjid literally means a place of prostration...
  
  s.
• The Sharia
  Sharia
  Sharia law, is the moral code and religious law of Islam. Sharia is derived from two primary sources of Islamic law: the precepts set forth in the Quran, and the example set by the Islamic prophet Muhammad in the Sunnah. Fiqh jurisprudence interprets and extends the application of sharia to...
  
  criminal offence of "close proximity" whereby two unmarried non-relatives of the opposite sex are apprehended after being found "in compromising positions" by state religious police.http://www.straitstimes.com/Breaking%2BNews/SE%2BAsia/Story/STIStory_429513.html http://thestar.com.my/news/story.asp?file=/2009/8/27/nation/4596776&sec=nationhttp://www.orientexpat.com/forum/5878-khalwat-close-proximity/