Hazrat Abdullah bin Shaddad (may Allah be pleased with him) narrates that a delegation from the Sarh tribe of Yemen came to the service of the Messenger of Allah (peace and blessings be upon him). The Messenger of Allah (peace and blessings be upon him) said to them: You must absolutely establish prayer and pay zakat. And listen and obey. Otherwise, I will send to you a man who is like me; he will fight your fighters and take your children as captives. By Allah! He is either me or someone like me. Then the Prophet (peace and blessings be upon him) took the hand of Hazrat Ali (may Allah be pleased with him).