that all the peoples of the earth may know the hand of Yahweh, that it is mighty; that you may fear Yahweh your God forever.
The notation that the crossing took place on the tenth day of the first month (Joshua 4:19) is significant. It was exactly 40 years earlier, to the day, that God instructed Israel to prepare to depart from Egypt by setting apart the paschal lambs (Exodus 12:3).