Joshua 4:20-24

And those twelve stones, which they took out of the Jordan, did Joshua set up in Gilgal. And he spake unto the children of Israel, saying, When your children shall ask their fathers in time to come, saying, What mean these stones? then ye shall let your children know, saying, Israel came over this Jordan on dry land. For Jehovah your God dried up the waters of the Jordan from before you, until ye were passed over, as Jehovah your God did to the Red Sea, which he dried up from before us, until we were passed over; that all the peoples of the earth may know the hand of Jehovah, that it is mighty; that ye may fear Jehovah your God for ever.