Iʿtikāf (Arabic: اعتكاف, also i'tikaaf or e'tikaaf) is an Islamic practice consisting of a period of staying in a mosque for a certain number of days, devoting oneself to ibadah during these days and staying away from worldly affairs. The literal meaning of the word suggests sticking and adhering to, or being regular in, something, this 'something' often including performing nafl prayers, reciting the Qur'an, and reading hadith.
Some Muslims claim that a performance of i'tikāf to a beggar sitting outside another's house, knowing that with persistence the occupant of the house will apparently give something to help. Others may claim that one can more easily identify when Ramadan's night of power will occur.
It is considered sunnah to perform i'tikāf for ten full days, these ten often being the last of the month of Ramadan; any ten consecutive days, however, may be chosen. I'tikāf may also be observed for three full days, often the 13th through the 15th of Ramadan, or for a full day from sunset to sunset, in each case supererogatorily. The shortest i'tikāf, also considered supererogatory, can be observed for the duration of time between two daily prayers (such as from Asr to Maghrib).
Because in every case except for the last, one ought to be fasting at the same time, performing i'tikāf on Eid al-Fitr or Eid al-Adha would not be permissible.
A person who wishes to take part in i'tikāf (a mu'takif) must be a sane and clean Muslim, not causing strife within the family in taking part, and unambiguously in the main masjid of the person's town or city (not any other place of congregation, though exceptions may be made in extraneous circumstances). The person must make the appropriate intention, either on the person's own behalf or on behalf of someone else unable to do so, to commit to staying inside the masjid for the entire period chosen for i'tikāf, except for very important or unavoidable reasons (such as buying food or attending a funeral). This intention must be made on the sunset prior to the first day of i'tikāf.
Most of i'tikāf consists of the persistent recitation of the Qur'an (without disturbing others if doing so loudly) and numerous du'a, whether in seeking forgiveness from Allah or otherwise, though other people may also study numerous hadith. Some who take part try to complete an entire reading of the Qur'an in the duration they have allotted for themselves.
Outside of these highly regarded actions, eating (when not fasting) and sleeping, changing clothes, clipping nails, trimming facial hair, and having religious discussions and lectures are generally permitted.
Much of what is prohibited in i'tikāf is often considered sacrilegious behavior in a holy time, such as speaking of worldly affairs, trying to seek pleasure in them, backbiting or otherwise telling lies, and remaining silent as a means to achieve ibadah. Outside of these, shaving facial hair, buying and selling anything, deriving pleasure from people not of one's gender, and discussions with the intent to display one's superiority in some fashion are generally prohibited. Performing any of these actions voids one's i'tikāf and often one is required to pay kaffara to compensate for this.
The usual actions that are prohibited in an Islamic fast are prohibited in i'tikāf.
A mu'takif may leave the place that the person chooses for i'tikāf for only very specific reasons. Except when responding to another person's greeting, one who must leave the place of i'tikāf must go out and return quickly, avoiding the shade and other human contact except when absolutely necessary.One may go out to perform wudu when the person is no longer in a state of ablution; performing it a second time (i.e. when the person is still in a state of ablution) isn't allowed.
One may take a shower, assuming such shower is available on the masjid's premises, only if the person has had a wet dream, a period, or something remotely similar. Though this shower may be combined with wudu, any other reason for taking such a shower isn't allowed.
One may leave for Friday prayers only right before the khutbah begins and must return right after the prayers have ended.
It is highly recommended that one leave, the person knowing that the i'tikāf will be voided, if one is ill or must help in tackling an emergency such as a fire or a person in distress.
If where multiple people are in i'tikāf one person must leave, then the rest are also obligated to leave in order to avoid 'usurping' the area where the first person was in i'tikāf.
If in performing i'tikāf one does something which voids it, one mustredo it completely, if sexual relations took place;
redo it completely, if the violation took place on any day except the last;
redo only the time lost, if anything not involving sex organs took place, or
redo one day's worth, if one has had a period.