Yahweh was all powerful. He would make all the small idol gods of the earth shrivel up. All the coasts and islands on earth would remain where they were, but they would bow down to Yahweh. This seems like an addition here to finish up the destruction of Moab and Ammon.
On this faithful day, the vineyards will shrivel up. Thousands of vines worth about $23,000 in silver shekels in today’s money would be abandoned to thorns and briers. Places that were hoed before would now be overrun with briers and thorns. People would be afraid to go there because of these briers and thorns. Only the cattle would roam all over the place. The sheep would also tread on any crops that might be growing. Things would be bad, as the land was devastated.