This final panel depicts a scene from the oracles of a prophet about whom we know nothing apart from his poetry. His poem, one long sustained speech, now constitutes chapters 40 through 55 of the book of Isaiah. We call this prophet Second Isaiah.
This prophet lived a generation or two after Jeremiah. The city of Jerusalem had been sacked, the temple destroyed, and the people carried into captivity in Babylon, a country far to the east and separated from Jerusalem by the vast and inhospitable Arabian desert.
Deutero-Isaiah knew that Yahweh had once rescued his people from slavery in Egypt, and he believed that God was capable of delivering his people again. He announced that Yahweh would process to Jerusalem -- not by the long tedious journey around the fertile crescent to the north, but directly through the desert. Obstacles would be removed, canyons filled in, channels of water provided, with shade trees lining the route. At the end of the journey would be a rebuilt Jerusalem, more splendid than it had ever been in former times.
At the bottom of the panel are building blocks haphazardly arranged, symbolizing a part of Jewish life that was now to be put behind them. "The way of Yahweh" lies before them, leading them by the shortest possible route to the new restored Jerusalem. The brilliant light emanating from its midst suggests a source other than the city itself.
In fact, God himself dwells in this Jerusalem. Perhaps it is the heavenly Jerusalem portrayed in the New Testament book of Revelation.