Musannaf Ibn Abi Shayba 22:284

Ali ibn Mushir narrated to us, from al-Shaybani, from Yasir ibn Amr, who said: I asked Sahl ibn Hunayf, "What did you hear the Prophet, may Allah bless him and grant him peace, mention regarding 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."