Musnad Ahmad 259:2

Yazid ibn Harun narrated to us, he said: Hammad ibn Salamah informed us, from Ali ibn Zayd, from Abu Burdah, who said: I passed by al-Rabadhah, and there was a tent. I said: "Whose is this?" It was said: "Muhammad ibn Maslamah’s." I sought permission to enter upon him, and I entered upon him. I said: "May Allah have mercy on you, you are in a position regarding this matter; if only you would go out to the people and command and forbid." He said: "The Messenger of Allah, peace and blessings of Allah be upon him, said: 'There will be a tribulation, a division, and a disagreement. When that happens, take your sword to Uhud, strike it against the rock until it breaks, then break your arrows, cut your bowstring, and sit in your house.' That has indeed happened." Yazid said at one point: "Strike it until it breaks, then sit in your house until a sinful hand comes to you, or Allah, the Mighty and Majestic, grants you well-being." He said: "What the Messenger of Allah, peace and blessings of Allah be upon him, said has happened, and I have done what he commanded me to do." Then he took down a sword that was hanging on the tent pole and drew it, and it was a sword of wood. He said: "I have done what the Messenger of Allah, peace and blessings of Allah be upon him, commanded me to do, and I have taken this to frighten the people with it."