Shall build the old waste places. — The prophet contemplates primarily the restoration of the public and private buildings of Jerusalem, but the words have obviously a wider spiritual application.
The foundations of many generations — i.e., those that had been lying in ruins, with no superstructure, for even a longer period than the seventy years of exile.
Thou shalt be called... — This was to be the special work, and was to constitute the enduring fame, of the new Israel.
Paths to dwell in — i.e., the streets of the city shall be once more flanked with houses on either side, and not merely roads from one point to another.