He stretched out his hand over the sea, he shook the kingdoms: the LORD hath given a commandment against the merchant city, to destroy the strong holds thereof.
He - Yahweh.
He shook the kingdoms - the Phoenician cities and colonies, Tyre, Sidon, Arad, Arce, etc.
The merchant city - Hebrew, Canaan, meaning the north of it; namely, time Phoenice of the Greeks, at the foot of Lebanon. On their coins they call their country Canaan.