Sunan Abi Dawud — Hadith #19416

Abu Dawud said; I was told from [Harun Ibnul Mughirah] he said; has told us [Amru bin Abu Qais] from [Syu'aib bin Khalid] from [Abu Ishaq] he said; While looking at his son Al Hasan, Ali radiallahu 'anhu said, "My son is a leader as mentioned by the Prophet sallallaahu 'alaihi wasallam, and from his descendants a man will come out with a name like the name of your Prophet, his morals are the same but not his body posture." Then he told his story, "He will fill the earth with justice." Harun said, "Has told us [Amru bin Abu Qais] from [Mutharrif bin Tharif] from [Abu Al Hasan] from [Hilal bin Amru] he said; I heard [Ali radliallahu 'anhu] say, "The Prophet sallallaahu 'alaihi wasallam said: "A man will come out from across the river (like Bukhara and Samarqan), his name is Al Harith bin Hurrats, then after him a man named Mansur will come out. He will strengthen Muhammad's family as the Quraysh strengthened the Prophet sallallaahu 'alaihi wasallam. So it is obligatory for every believer to help him, or he said: "fulfill his call