Joshua 4:21

19The people came up out of the Jordan on the tenth day of the first month, and encamped in Gilgal, on the east border of Jericho.

20Joshua set up those twelve stones, which they took out of the Jordan, in Gilgal.

21He spoke to the children of Israel, saying, “When your children ask their fathers in time to come, saying, ‘What do these stones mean?’

22Then you shall let your children know, saying, ‘Israel came over this Jordan on dry land.

23For the LORD your God dried up the waters of the Jordan from before you until you had crossed over, as the LORD your God did to the Red Sea, which he dried up from before us, until we had crossed over,