The Promised Deliverer (Kitab Al-Mahdi)

Dawud :: Book 36 : Hadith 4277

Narrated Ali ibn AbuTalib:

The Prophet (peace_be_upon_him) said: A man called al-Harith ibn Harrath will come forth from Ma Wara an-Nahr. His army will be led by a man called Mansur who will establish or consolidate things for Muhammad's family as Quraysh consolidated them for the Apostle of Allah (peace_be_upon_him). Every believer must help him, or he said: respond to his sermons.