I shall mention the conditions upon which the scholars agree, preponderant conditions and outweighed conditions.
First: There is only one pillar for I‘tikaaf (seclusion in the mosque). Some scholars have stated there are four or five, but the sound opinion is that it is one single pillar, which is staying in the mosque and abiding therein for the sake of obeying and worshipping Allah The Almighty. This pillar is an important rule that tells us that whoever fails to fulfill it is either negligent or invalidates his I‘tikaaf altogther.
Second: Conditions of I’tikaaf, which scholars agree are five: Being Muslim, having sound reasoning, discernment, the intention to do so and that it be practiced in the mosque. Someone may say that being in the mosque need not be mentioned here because it is an essential pillar, however, some scholars mentioned it for the sake of emphasizing its importance so that no one would stay in a place of worship in his home or anywhere else and say that he has made I‘tikaaf.
Conditions about which there is difference in opinion among scholars and that are preponderant are: Purity from menstruation and post-partum bleeding and Janaabah (post-sexual impurity). Added to this is the permission of the master and the husband for the slave and wife respectively.
These are the preponderant conditions.
Then there are conditions about which there is a difference in opinion among scholars and that are outweighed, include that one be fasting. This is a highly controversial issue that is related to I‘tikaaf as some say that I‘tikaaf is not valid without the person being fasting. However, there is no clear authentic proof that this is a condition of the validity of I‘tikaaf. Scholars who are of the opinion that fasting is not a condition build their stance on the Hadeeth of ‘Umar, may Allah be pleased with him, when he said that he had vowed to make I‘tikaaf for one night in Al-Masjid Al-Haraam (the Grand Mosque in Makkah). It is known that the night is not a time for fasting and so fasting cannot be a condition of the validity of I‘tikaaf since making I‘tikaaf at night is proven to be valid although the night is not a time for fasting.
The I‘tikaaf of the Woman With Vaginal Bleeding Outside the Menstrual Period
Scholars hold different opinions on this issue and the sounder opinion is that the I‘tikaaf of the woman with vaginal bleeding outside the menstrual period is permissible. It was proven on the authority of ‘Aa’ishah, may Allah be pleased with her, in a Saheeh (Authentic) Hadeeth that she said, “One of the wives of the Prophet once made I‘tikaaf with him and she would see yellowish and reddish secretions and would perhaps put a bowl beneath her while praying.” [Al-Bukhari] She would do this so as to not sully the mosque. Thus, the women who experiences vaginal bleeding outside the menstrual period is permitted to make I‘tikaaf, provided that she is careful not to dirty the mosque with any impurity, just as she is permitted to pray, fast and have sexual intercourse with her husband. The ruling of such a woman applies also to the one who suffers from urinary incontinence, pre-ejaculatory fluid and the one who has a bleeding wound. However, all such people must be careful not to dirty the mosque with any impurity.