https://abukhadeejah.com/isis-in-iraq-syria-ibn-kathir-died-774-ah-if-the-khawaarij-ever-gained-strength-in-iraq-and-syria-there-would-be-mass-killing/
The Khawarij Past and Present: ISIS Daesh in Iraq & Syria: Ibn Kathir (died 774 AH): If The Khawarij Ever Gained Strength in Iraq and Syria, There Would Be Mass Killing