Albert Barnes Commentary Ezekiel 39:6

"And I will send a fire on Magog, and on them that dwell securely in the isles; and they shall know that I am Jehovah." — Ezekiel 39:6 (ASV)

The judgment is extended to “the isles” (or, seacoast) to show that it should fall not only on Gog and his land, but on those who share Gog’s feelings of hatred and opposition to the kingdom of God.