What's with the stones, dad?

This text speaks for itself:

God instructs Joshua, "Select twelve men from the people, a man from each tribe, and tell them, 'From right here, the middle of the Jordan where the feet of the priests are standing firm, take twelve stones. Carry them across with you and set them down in the place where you camp tonight.'"

"When your children ask you, 'What are these stones to you?' you'll say, 'The flow of the Jordan was stopped in front of the Chest of the Covenant of God as it crossed the Jordan—stopped in its tracks.'"

"God, your God, dried up the Jordan's waters for you until you had crossed, just as God, your God, did at the Red Sea, which had dried up before us until we had crossed. This was so that everybody on earth would recognize how strong God's rescuing hand is and so that you would hold God in solemn reverence always."