There is so much going on in the story of the fall of Jericho.
The spies find shelter in the home of a prostitute and in exchange for her help, promise safety to her and her family.
The spies report back.
The people cross the rive and march around the city and finally make a loud noise of praise to God and the walls fall down.
This is the moment when the people of Israel really arrive in land that God has promised. They have come in, and they have brought down the most fortified city. There are more fights and they have to establish which tribes get which land, but this is the point where the people begin to see that it is really going to happen. They are really going to live in the land that God promised to Abraham.