Sunan Ibn Majah, Chapter: The Chapters on Tribulations

"I entered upon Muhammad bin Maslamah and he said that the Messenger of Allah (saw) said: 'There will be tribulation, division and dissension. When that comes, take your sword to Uhud and strike it until it breaks, then sit in your house until there comes to you the hand of the evildoer (to kill you) or a predestined (natural) death.'" "And that came to pass, and I did as the Messenger of Allah (saw) said."