Muhammad al-Baqir
According to Ja'far al-Sadiq, the sixth in the chain of the twelve imams of the Shia, Mahdi will appear on a Friday. Muhammad al-Baqir also emphasizes on the day of Ashura being the day of the uprising. His reappearance will be announced from the heavens. Muhammad al-Baqir says regarding the reappearance of Mahdi, “The Mahdi (‘a) will rise up at a time when the helm of affairs would be in the hands of tyrants.”