Where does the expression “from Dan to Beersheba” come from and What does it mean?

The expression “from Dan to Beersheba” means all over the world; from one side of the world, or the country to the other.

The expression comes from the Bible, Judges xx, 1, telling of the assembly of Israelites from one end of the country to the other to do battle against the Benjamites, from the city of Dan at the north end of the Land of Israel and from the city of Beersheba at the south end, and all points between.

As far as the Israelites were concerned, that area embraced the world.