Musnad Abu Ya'la al-Mawsili 152:334

Abu Musa narrated to us, Abu Bakr ibn Ayyash narrated to us, Asim narrated to us, from Zirr, from Abdullah, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "A people will emerge at the end of time, young in age and foolish in intellect. They will speak with the best of speech. They will recite the Quran, but it will not go beyond their throats. They will pass through Islam just as an arrow passes through the game. So whoever encounters them, let him fight them, for in killing them there is a reward with Allah for whoever kills them."