Charles Ellicott Commentary Jeremiah 25:22

"and all the kings of Tyre, and all the kings of Sidon, and the kings of the isle which is beyond the sea;" — Jeremiah 25:22 (ASV)

The isles which are beyond the sea.—Better, island. The Hebrew word is in the singular and is properly, as in the margin, a “region by the seaside”—a “coastland,”—and thus wider in its extent than our “island.”

Here, the position in which it occurs tends to identify it either with Cyprus, the coast of Cilicia, or Phoenician colonies generally in the Mediterranean. Cyprus seems the most probable of these.