Therefore everyone who hears these words of mine and puts them into practice is like a wise man who built his house on the rock.
Here we are drawing close to the end of the Sermon on the Mount.
There have been several different teachings that have rocked the foundations of the listeners in that day, and are still rocking the foundations of the listeners today. But right at the end Jesus tells us probably the most important point of the entire Sermon: the wise man is the one who "...hears these words of mine and puts them into practice."
Now, most of my life I was focusing on the rock and the sand. I can even remember teaching people that the rock was Jesus himself, but in this example, the rock, the sure foundation of living isn't Jesus; it is hearing the words of Jesus and applying them to your life.
You are wise if you are doing, not just hearing.