The Promised Deliverer (Kitab Al-Mahdi)

Dawud :: Book 36 : Hadith 4276

Narrated Ali ibn AbuTalib:

AbuIshaq told that Ali looked at his son al-Hasan and said: This son of mine is a sayyid (chief) as named by the Prophet (peace_be_upon_him), and from his loins will come forth a man who will be called by the name of your Prophet (peace_be_upon_him) and resemble him in conduct but not in appearance. He then mentioned the story about his filling the earth with justice.