The Prophet (PBUH): Trapped inside a cave

Narrated Ibn 'Umar:
Allah's Apostle said, "While three persons were traveling, they were overtaken by rain and they took shelter in a cave in a mountain. A big rock fell from the mountain over the mouth of the cave and blocked it. They said to each other, "Think of such good (righteous) deeds which, you did for Allah's sake only, and invoke Allah by giving reference to those deeds so that Allah may relieve you from your difficulty ..