I. Imam Mahdi’s (AS) Occultation

Imam Ali Ibn Abi Talib (AS) has brought up the subject of Imam Mahdi (AS)’s occultation in different occasions within the limits of his audience intellectual and understanding abilities and according to the natural trend of events in the future.
On an occasion he points to the necessity of the existence of a divine Hujjah on the earth, even more, in the entire universe. Then he notes that this Hujjah may be present and apparent and may be hidden from the people’s sight because of the situation not being suitable. The Imam (may God hasten his reappearance) declared that during the time of occultation, even though his body cannot be sighted and is not present, his knowledge will be known to the people.[1]
On the second occasion, Imam Ali (AS) emphasized that the Mahdi (may God hasten his reappearance) is one of us, the Ahlul-Bait, and he will fill the earth with justice and equity after it being filled with oppression.[2]
Finally, on the third occasion, he mentions the hardships and problems of the time of occultation and the characteristics of the people of that time saying at the end that many people will go astray or lose hope and start denying His Eminence.[3]
II. The Causes and Philosophies behind the Occultation

Even though some traditions clearly state that the actual philosophy of occultation is not known for mankind, some of Imam Ali’s (AS) sayings point out a few. Some of these are: the Imam (may God hasten his reappearance) not having to pledge allegiance to the oppressors, the distinction of the deceived, the oppression of people and the children of Imam Ali (AS) by people themselves, and the perseverance of the signs of guidance.
III. The Signs of the Era of Occultation

There are interesting face that can be found in Imam Ali’s sayings about the signs and dangers for the intellect and belief in the era of occultation. Some of these are the wonderment of the people and their being lost, having difficulties in being religious and, hesitance in the existence of the Imam (may God hasten his reappearance).
[1] Kulaini, Al-Kafi, Vol. 2, P. 139
[2] Allameh Majlesi, Biharol-Anwar, Vol. 51, P. 118
[3] Ibid., Vol. 38, P. 70; Vol. 51, P. 119