Sahih Muslim Book 20, Hadith Number 4716.

Chapter : Saying of the Holy Prophet (may peace be upon him): “A group of people from my Umma will always remain on the right path and continue to be triumphant.’ their opponents shall not be able to do them any harm.

It has been narrated on the authority of Mughira who said: I heard the Messenger of Allah (may peace be upon him) say: A group of people from my Umma will continue to be triumphant over the people until the Command of Allah overtakes them while they are still triumphant. The same tradition has been narrated through another chain of transmitters on the same authority.