“Narrated to us Abdullah Ibn Abi Huzail: I asked Jafar Sadiq about the evidence of Mahdi. He said to me:

“Surely, its evidence is that he [Mehdi] is the proof upon the believers,” that is, the one who introduces proofs to them, “the establisher of the affairs of the Muslims,” that is, the one who practises the provisions of God, which is the Qur’an, in life, in other words, the one who introduces them into life, “speaks with the Qur’an”; notice that he does not speak superstitions,“knower of Divine Laws”, that is, the provisions of the Qur'an, “his caliph upon his nation”, he discharges the duties of our Prophet (saas), ”and his successor upon them and his administrator who is unto the Prophet (s.a.w.s) as Harun (a.s) was to Musa (a.s).” What did Musa (as) say? He said,“You will obey my brother. This is obligatory upon you.” What does our Prophet (saas) say? He says, “You