It relates the story of a number of faithful young men who lived in a disbelieving village/city. They eventually made up their minds to abandon their village and flee to Allah with their faith after they were confronted by their own people lead by the aggressive and unjust ruler. Then they were rewarded by Allah the Almighty Who showered upon them His Mercy in the cave and ordered the sun not to harm them in any way and they were overcome by sleep for a long time. After they were awaken up by Allah the Almighty, they found that faith has entered the hearts of the people of their own village/city, all of them and the ruler became one of the faithful as well. That was their reward!