Joshua 4:20-24

20And those twelve stones, which they took out of Jordan, did Joshua set up in Gilgal. 21And he spake unto the children of Israel, saying, When your children shall ask their fathers in time to come, saying, What mean these stones? 22Then ye shall let your children know, saying, Israel came over this Jordan on dry land. 23For the LORD your God dried up the waters of Jordan from before you, until ye were passed over, as the LORD your God did to the Red Sea, which he dried up from before us, until we were passed over: 24that all the peoples of the earth may know the hand of the LORD, that it is mighty; that they may fear the LORD your God for ever.