Abu Dawud said: Abu Ishaq told that Ali looked at his son al-Hasan and said: This son of mine is a sayyid (chief) as named by the Prophet ﷺ, and from his loins will come forth a man who will be called by the name of your Prophet ﷺ and resemble him in conduct but not in appearance. He then mentioned the story about his filling the earth with justice.
Hadith Referenceسنن ابي داود / كتاب المهدى / 4290
Hadith Gradingالألبانی:ضعيف | زبیر علی زئی:ضعيف, إسناده ضعيف, أبو داود لم يدرك ھارون،فالأول منقطع و أبوإسحاق عنعن ولم يسمعه من علي رضي اللّٰه عنه،والثاني فيه أبو الحسن الكوفي وھلال بن عمرو مجهولان (تقريب التهذيب: 8051،7345), انوار الصحيفه، صفحه نمبر 152