Hadith of the out-loud calling

I heard an old man mentioning from Saif bin Umair who said, ‘I was in the presence of Abu Al-dawaniq, so I heard him saying, initiating it himself, ‘O saif Bin Umair! It is necessary for a caller to call in the name of a man from the sons of Abu Talib (as)’. I said, ‘Does any one from the people report it?’ He said, ‘By the One (azwj) in Whose Hand is my soul, my own ears have heard it from him (asws) (Abu Jafar (asws)) saying: ‘It is a must that a caller calls out in the name of a man’. I said, ‘O commander of the faithful! As for this Hadith, I have not heard similar to it at all’. He said to me, ‘O Saif! If it was like, so we would be the first ones to respond to it. But rather he would be one of the sons of our uncle’. I said, ‘Which son of your uncle?’ He said, ‘A man from the children of Fatima (sa)’. He then said, ‘O Saif! Had I not heard it from Abu Ja’far (asws) Muhammad Bin Ali (asws) saying it, however, if it were narrated to me by the inhabitants of the earth, I would not have accepted it from them, but it is from Muhammad Bin Ali (asws)’.