Foundations and Purposes of Imam Mahdi’s (a) Global Governmen
The signs before reappearance of al-Mahdi (AS)
There are many traditions narrated by all Islamic schools where the Apostle of Allah (PBUH&HF) has portrayed the events just prior to the uprising of al-Mahdi (AS). The Shi'ite traditions that have been narrated from the Prophet (PBUH&HF) and the Imams of Ahl al-Bait (AS) provide much more details for the events that are supposed to take place before the reappearance of Imam al-Mahdi (AS). Some of these signs are about the hard condition of people in the world before his reappearance. For instance, Abu Hamza al-Thumali and Abu Basir both narrated:
Imam Muhammad al-Baqir (AS) said, "The Qa'im shall not rise until after a great fear from people, the earthquake, afflictions, trials, and the disease have inflicted people, the war between Arabs, great disagreement between people, break ups in their religion, changing their state such that the wishers wish death every morning and night due to the greatness of what is observed, and the eating of people by people. The rising of (al-Qa'im) shall be at the time of despair and hopelessness of people for finding any opening/relief."
On the other hand, some signs are about the miraculous events that will happen just prior to the rising of al-Qa'im. For instance, there will be a lunar eclipse at the end of the month of Ramadhan. The eclipse at the end of the month is a supernatural phenomenon that has never happened before. Badr Ibn Khalil al-Azdi narrated:
I was sitting with Imam Muhammad al-Baqir (AS) when he (AS) said, "There shall be two signs before the rising of al-Mahdi (AS) that have not occurred since Adam (AS) descended on the earth. The sun shall be eclipsed in the middle of the month of Ramadhan and the moon (shall be eclipsed) in the end of that month." A man in the presence said, "O Son of the Apostle of Allah (PBUH&HF)! The sun shall be eclipsed in the end of the month and the moon in the middle." The Imam replied, "I know what you say. But these are the signs that have never happened since Adam descended."
The possibility of canceling the signs of the reappearance
The reported signs were the information that Allah willed about their occurrence in future and were in effect at the time that the Imams (AS) spoke about them. In other words, with their vision in the knowledge of what had been willed to happen, the Imams (AS) mentioned some of the signs that Allah had willed and planed at that time. However, Allah has not promised the occurrence of the planned signs, and thus all such signs are subject to change due to Allah's new decision (al-Badaa).
The traditions state that amongst all the signs there are few sings that are definite, which means it is unlikely that Allah changes His will on their occurrence. Thus, they are very likely to take place before the advent of Imam al-Mahdi (AS). Umar Ibn Hanzala narrated:
Imam al-Sadiq (AS) said, "There are five definite signs before the rising of al-Qa'im, which are: (the rising of) al-Yamani and al-Sufyani, the (heavenly) cry/call (by Gabriel which will be heard all over the world), the murder of Nafs al-Zakiyya, and the sink (of the Sufyani army) into (the land of) al-Baydaa (located between Mecca and Medina)."
Even for such definite signs Allah reserves al-Badaa. Al-Badaa is the origination of a new plan by Allah. We will discuss the phenomenon of al-Badaa and its significance in the next section. Allah may change those of the definite wills that are not categorized as His Sunan or His promises. For instance, Allah informed us through His Apostle (PBUH&HF) that before the reappearance of Imam al-Mahdi (AS), al-Sufyani would certainly rise. This is a definite will, but it is not categorized as a promise. It is just an insisted future event meaning that it is unlikely that Allah cancels His permission for the occurrence of this event, though it is still possible. According to the following tradition, Allah may make Badaa even in such insisted news. Dawud Ibn al-Qasim al-Ja'fari narrated: