nations, and their countries. Hebrew. ha-arazoth... 'arzam: as in Isaiah 37:11. The latter word put by Figure of speech Metonymy (of Adjunct), for the people inhabiting the lands. Note also the Figure of speech Paronomasia. Some codices read "nations, and their land".
Related Commentaries of Isaiah 37:18
Isaiah 37:18
18 Of a truth, LORD, the kings of Assyria have laid waste all the nations,d and their countries,