Holy Prophet (sawa) said, “When I was taken up to the heavens in Meraj, I was called. I said: “Yes, my Lord, You are Blessed and High.” Then I was called again: O Mohammed, You are My servant and I am your Lord. Then worship Me and rely on Me. You are My Light among My creatures, and My proof among the people. I have created Paradise for you and your followers and created Hell for those who oppose you. I have made it incumbent to honor your Trustees and have assured reward for their followers.”Then I asked: “O Lord, who are my trustees? I was told, “O Mohammed, the names of your trustees are recorded on the base of My Throne.” When I was in front of my Lord – the Exalted the Magnificent – I looked at the base of the Throne and saw twelve Lights. Over each Light there was a green line on which the name of one of my Trustees was written. The first of them was Ali Ibne Abi Talib (as). The last one was the Mahdi of my nation.
Then I asked: “O Lord, are these the trustees after me?” I was told, “O Mohammed, they are My Trustees, loved ones, chosen ones and proofs from My creatures after you. They are your Trustees and successors and are the best of the people after you. I swear by My honor and majesty that I will make My religion victorious by means of them. I will announce My word by them. I will cleanse the earth from My enemies by the last one of them (Imam Mahdi). I will rule the east and the west of the earth by him. I will make the winds subdued to him. I will debase tough clouds for him. I will raise him up to the heavens and assist him with My Troops. I will assist him with the angels so that he propagates My invitation and unites the people concerning My Unity. Then I will extend his rule and continue the times under the control of My friends until Judgment Day.” (Beharul Anwar, volume 52, chapter 32, tradition 5)