Musannaf Ibn Abi Shayba 38:126

'Ali ibn Mushir narrated to us, from al-Shaybani, from Usayr ibn 'Amr, who said: I asked Sahl ibn Hunayf, "Did you hear the Prophet, may Allah bless him and grant him peace, mention these Khawarij?" He said: I heard him—and he gestured with his hand toward the east—saying: "There will emerge from it a people who recite the Quran with their tongues, but it will not pass beyond their throats. They will pass through the religion just as an arrow passes through the game."