Sunan Ibn Majah, Chapter: The Chapters on Tribulations

that the Messenger of Allah (saw) said: that the Messenger of Allah (saw) said:"There will be callers at the gates of Hell; whoever responds to them they throw them into it." I said: "O Messenger of Allah, describe them to us." He said: "They will be from our people, speaking our language." I said: "What do you command me to do, if I live to see that?" He said: "Adhere tothe main body of the Muslims and their leader. If there is no such body and no leader, then withdraw from all their groups, even if you bite onto the trunk of a tree until death finds you in that state."