Answer: The summary is in the explanation.
Explanation: Jesus was telling a story of two builders. One of the two builders was a foolish man who built his house on sand. The second builder was a wise man who built his house on rock. When a storm came, the house on sand was destroyed. He told this story to us so that our foundation in him was strong and not weak like the person who built his house on sand. I don't know if this is what you wanted but this is how I interpreted it.