Instructions to Ibn Abbas before talks with the Kharijites

Given to ‘Abdullāh ibn al-‘Abbās, at the time of his being deputed to confront the Khārijītes.

Do not argue with them by the Qur’ān because the Qur’ān has many faces. You would say your own and they would say their own; but argue with them by the sunnah, because they cannot find escape from it.