Different types ofI’tikaaf

Waajib (obligatory):this can only be as the result of a vow. Whoever vows to do I’tikaaf isobliged to do it. The Prophet, Peace and Blessings of Allah be uponhim,  said:“Whoever vows to obey Allah, let him obey Him; and whoever vows todisobey Allah (commit a sin), let him not do that.” According to ahadeeth, Ibn ‘Umar, May Allah be pleased with him, said: ‘Umarasked the Prophet, Peace and Blessings of Allah be upon him,, “I made a vow during the Jaahiliyyah to spend one night in I’tikaafin al-Masjid al-Haraam.’ He said, ‘Fulfil your vow.’” (al-Bukhaari,4/809).

Mandoob (recommended):This is what was the habit of the Prophet, Peace and Blessings ofAllah be upon him,when he did I’tikaaf during the last ten days of Ramadhan, and hepersisted in doing this. It is Sunnah Mu’akkadah (confirmed Sunnah)which is known from his life, Peace and Blessings of Allah be uponhim, , as was reported in the ahaadeeth referred to when wediscussed the fact that I’tikaaf is prescribed in Islam.