Abdullah ibn Amr (may Allah be pleased with them both) who said: The Messenger of Allah (sallallahu 'alayhi wa sallam) said: "There will be a fitna that will cleanse (tastanzifu) the Arabs - its dead will be in the Hellfire. During this time the tongue will be more severe (ashad) than a blow of the sword.

At-Tuwaijari's Itihaf al-Jama'ah, I, pp. 75-81