23 Because God dried up the Jordan until they passed over, just as he did the Red Sea until they had gone over.
24 So that all the people on earth will know God's hand and fear him forever.
A few more words about this episode
Many years from now when children ask their fathers, saying, "Why are these stones here?"
This reminded Carole of the same question the children would ask about the Passover. And she was right about that. God told the Israelites to kill a lamb and smear its blook on the top and sides of the door. And they were supposed to do this every year at Passover forever.
When your children ask you, "Why are you doing this?", God said to say to them, "Because God passed over our houses when he was killing Egyptians and didn't kill any of us." (Exodus 12:21-27, Episode 29)
Apparently, however, Jews stopped wiping the blood on their door posts during the Passover once the tabernacle was established, and sacrifices were only made by priests in the temple. Wikipedia: Passover