The Apostle of Allah (PBUH&HF) said, "Even if only one day has remained for the duration of the world's existence, Allah shall prolong that day to send a person from my Ahl al-Bait whose name is the same as my name… He shall fill out the earth with peace and justice just as it has been filled with injustice and tyranny."
"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."
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."