What’s Up With the Ending?

Ezekiel's book ends with nine chapters devoted to the rebuilding of the future Temple; the various rules governing sacrifices and festivals and how to worship God correctly; and describing how the land will be divided between the twelve tribes of Israel. It's a blueprint for the future: the House of Israel has just suffered a massive defeat, and Ezekiel's giving them the tools to rebuild. The last verse lets us know the reason for all these instructions and measurements:

The circumference of the city shall be eighteen thousand cubits. And the name of the city from that time on shall be, The LORD is There. (48:35)

Restoring God's presence to Jerusalem—publicly—is the point.