I asked Suhayl bin Hunayf, "Did you hear the Prophet ﷺ say anything about the Khawarij?"He replied, "I heard him say, while gesturing with his hand toward Iraq, 'A people will emerge from there who recite the Quran, but it will not pass beyond their throats. They will pass out of Islam as an arrow passes through its target.'"
قلت لسهيل بن حنيف: هل سمعت النبي ﷺ يقول في الخوارج شيئا؟ قال: سمعته يقول- وأهوى بيده قبل العراق-: يخرج منه قوم يقرؤون القرآن، لا يجاوز تراقيهم، يمرقون من الإسلام مروق السهم من الرمية.
Bukhari narrated it in the Chapter on Calling Apostates Back to Repentance (6934), and Muslim in the Book of Zakat (1068:159), both from the hadith of Abdul-Wahid, who said, Sulayman Shaybani told us, Yasir bin Amr told us, and he related it. The wording given is that of Bukhari.Muslim also narrated it (1068:160) through the route of Yazid bin Harun, from Awwam bin Hawshab, who said, Abu Ishaq Shaybani told us, from Usayr bin Amr, from Sahl bin Hunayf, with the second wording.