My father narrated to us. He said: Sa`d b. `Abdullah narrated to us from Ahmad b. Muhammad b. `Isa from al-Hasan b. `Ali b. Faddal from `Ali b. Abi Hamza from Abi Basir. He said:

I said to al-Sadiq Ja`far b. Muhammad : Who are the Family of Muhammad (Aali Muhammad)? He said: His descendants. I said: Who are his Ahl al-Bayt? He said: The deputed Imams. So, I said: Who is his progeny (`itra)? He said: The people of the cloak (al-`aba’). So, I said: Who is his Nation (Umma)? He said: The believers who affirmed what he came with from Allah, who grasp onto the two heavyweights that they were ordered to grasp onto, the Book of Allah and his progeny, his Ahl al-Bayt, from whom Allah has removed uncleanliness and purified with a thorough purification. They are the two vicegerents (khalifatan) over the Nation after the Messenger of Allah (s).