The remnant that is escaped (see the comment on Isaiah 37:4). Take root downward, and bear fruit upward; i.e. "spread over the land, and became firmly rooted in it, and flourish as in the former time."
We must conceive of the Assyrians having, in their two recent invasions, completely depopulated the country districts. Numbers had, no doubt, been slain; more than two hundred thousand had been carried into captivity; a portion had found refuge in the capital On the withdrawal of the Assyrians, these last "went forth," reoccupied their lands, and rebuilt their towns and villages.
The blessing of God was upon them, and in a short time Judaea recovered her ancient vigour, so that, under Josiah, she was able to extend her dominion over almost the whole of the old Israelite territory (2 Chronicles 34:6, 2 Chronicles 34:18).