It was said in Falaahi Ssa'il that the most important supplication after (Zuhr) noon prayer is to imitate Imam Sadiq (peace be upon him) in his supplication for Imam Al-Mahdi (peace be upon him) which the Prophet has given his glad tidings to his nation in the authentic narrations, Prophet has promised his nation that Imam Al-Mahdi will appear prior to the last hour as Muhammad bn Rahban Dabili has reported:
On the authority of Ibad bn Muhammad Mada'in, he said: I entered to Abu Abdullah in Medina when he finished his noon prayer and I met him raising his hands to the Heaven offering the following supplication:
I said to Imam: May my soul be sacrificed for you, isn't you have prayed for yourself? He said: I have prayed to the light of the progeny of Muhammad (peace be on them) who shall retaliate against their enemies with the command of Almighty Allah.
I said: when will he be coming out?
When the owner of creations and command wishes, Imam replied. I said: what are the signs before then? He said: the signs are many and different. I said: like what? Imam Sadiq (peace be upon him) said: A banner shall come out from the east and west, sedition will persist and a man shall come out from Yemen among the descendant of my uncle Zaid, and there shall be plunding of the house properties then Allah will act according to his wishes.