Fourth...
Fourth, the Imamate is divine covenant, bestowed only on the just the pious, and the utterly pure; it is only they who aid and guide the ummah. The imamate is not then a station which is at the disposal of men to be awarded to whomever they see fit.
Fifth, prophethood and Imamate can be combined in a single person, as was the case with Ibrahim for he had already received revelation in his capacity of prophet correctiong men's erroneous beliefs by means of decisive arguments and proofs, and in the very process of doing this, he had acquired the strength and capacity needed for inner guidance, so that the gate of Imamate was opened before him.
Finally, the verse indicates that members of Ibrahim's progeny who are not wrongdoers (zalimin) will be granted the station of Imamate. There can be no doubt that the most righteous of God's servants from among that progeny were the Prophet, peace and blessings be upon him and his family, and the Inerrant Imams, so they must count as Imams from Ibrahim's line who were entrusted with inner guidance and the knowledge of the unseen.
( 160 ) Imam Ja'far al-Sadiq peace be upon him is reported in al- Kafi to have said: "Before appointing Ibrahim as prophet God Almighty appointed him His servant. Before ennobling him with His friendship He bestowed on him the rank of messengerhood. Before granting him the rank of Imamate He made him His sincere and devoted friend.
It was therefore after Ibrahim had attained a whole series of high ranks that he was given the station of Imimate." ( 1 ) Numerous traditions exist affirming and emphasizing the need for an Imam to be present among the people in order to guide them. These traditions indicate that as long as the human species exist in this world a proof of God and the truth must also exist to provide and protect the intellectual social and credal framework for the ummah.
This proof is none other than the Imam the Friend of God who in his very person is a living exponent and exemplar of true Islam.
The Commander of the Faithful 'Ali peace be upon him said: "The Family of Muhammad peace and blessings be upon him and his family are like the stars; as soon as one of them sets another rises." ( 2 ) Imam Ja'far al-Sadiq peace be upon him said in the course of a sermon: "God has illumined His religion with the Imams from the Household of the Prophet and made them the abundant spring from which knowledge of religion gushes forth.