The meaning of ‘I’tikaaf’ is to seclude oneself in the Mosque, with the express intention (Niyyat)of ‘I’tikaaf’. According to the Hanafi school of thought, this may be of three different types:
a) Waajib I’tikaaf (Obligatory I’tikaaf)
I’tikaaf becomes compulsory when a person makes it obligatory upon himself. For example, when a person makes a vow to Allah that if Allah fulfils a certain wish of his, he shall perform so many days ‘I’tikaaf’, in this case, the moment his wish is fulfilled, the I’tikaaf becomes compulsory. Or a person may just make an unconditional vow, whereby he makes I’tikaaf Waajib upon himself for a certain number of days; this becomes obligatory for him from that moment onwards.
b) Sunnat I’tikaaf
This was the general practice of the Holy Prophet (SAW). It means to seclude oneself in the Masjid for the last ten days of Ramadhaan.
c) Nafl I’tikaaf
For the third category i.e. Nafl I’tikaaf, no special time and no specific number of days are fixed. A person may make a Niyyah (intention) for any number of days at any time, even for his whole life.
While Imaam Abu Hanifa states that I’tikaaf must be for not less than a full day, Imaam Muhammad states that there is no limit as to the minimum period of time. The ‘Fatwa’confirms this latter view. Therefore, it is desirable for anyone entering a Masjid to make the ‘Niyyah’ (intention) of I’tikaaf for the period that he will remain in the Masjid; so that, while he is in Ibaadah, he also earns the reward of I’tikaaf.