Conditions of Itikaf (Part 1)
There are a few conditions for the person who wishes to partake in the Divine blessing of Itikaf:
1. Intelligence (Aql): Thus, the person must not be mentally unstable;
2. True Faith (Iman): Thus, although a Non-Muslim can perform the Itikaf and it may be correct from the point of view of the outer actions, however to earn the Divine Reward, he or she must be a true believer;
3. Intention (Niyyat): Itikaf must be performed for the purpose of seeking closeness to Allah (Glory and Greatness be to Him) and not to show off or due to societal or family or peer pressure;
4. Fasting (Sawm) During Itikaf: The person who is not able to fast, for whatever reason, is deprived from the Divine grace of being able to perform Itikaf. He or she may still gain a reward from Allah (Glory and Greatness be to Him) for having the intention to perform this act of worship, however can not directly participate in this act as will be mentioned. Therefore, if a person is a traveler or one who is not able to fast due to some danger to his life, he can not partake in Itikaf. However, if the traveler who wants to perform the Itikaf makes an oath that he will fast for three days on a trip, then he can perform the Itikaf even though his salat may be prayed as that of a traveler. In addition, if one needs to perform any sort of fasting whether it be obligatory, recommended, a penitence for a missed fast, on behalf of someone else, etc… then one’s Itikaf will be correct with the performance of this type of fast.
5. Permission: One must have the permission of the person whom he needs to gain permission from to carry out this act (guardian, husband, etc…) to ensure the correctness of the Itikaf.
6. Place: One must stay inside the Masjid for the entire period for his Itikaf to be correct (the rules of this will be explained in more detail later…)
Time Period (Length) of the Itikaf
The person performing Itikaf must stay in this state for a minimum of three complete days from sunrise of the first day until the sunset of the third day (for example if he starts Itikaf on Monday at Fajr time, he must complete it until Wednesday at Maghrib time).
The first two days of Itikaf are recommended and if a person wishes, he may leave after this period and end his Itikaf, however if he completes two full days of Itikaf in the Masjid (until the Maghrib of the second day), then it becomes obligatory upon him to continue his fast on the third day and to stay in the Masjid for the remaining period of his Itikaf – meaning till the time of Maghrib of the third day. Similarly, if a person goes into Itikaf for 5 days, the 6th day becomes obligatory; and if he goes into Itikaf for 8 days then the 9th day becomes obligatory and so on. Thus, Itikaf is for 3 full days and 2 nights which are in between these days and this period must be maintained. In this ruling, just as that of the daily Salat, the meaning of three complete days means three periods of Fajr to Maghrib.
Time of Itikaf
Anytime in which fasting is permissible is an opportune time for Itikaf and the state of Itikaf does not have a specific time related to it.
Of course the “White Days” which are the 13th, 14th and 15th of the lunar month and the last ten days of the Month of Ramadhan are the best times for this spiritual exercise.
Therefore, one can not make Itikaf on the day of `Eid since it is forbidden to fast on that day and similarly, he can not start Itikaf two days before `Eid. It has been mentioned that the Prophet of Islam (blessings of Allah be upon him and his family) used to perform Itikaf in the Month of Ramadhan in the first 10 days (three days), the second 10 days (three days) and then in the last ten days (three days) as well.
Source: coiradio.com
Other links:
Prayers: What Is The Philosophy Behind Wudhu And Ghusl?
What Is The Need To Face The Qiblah In The Prayers?
Why Should We Offer Prayers At Prescribed Times?
What Is The Philosophy Behind Tayammum ?
Why does Zakat become Wajib?