Syria. Probably Edom (for Aram). See note below.
Elath. It had belonged to Edom (2 Kings 14:22).
Related Commentaries of 2 Kings 16:6
2 Kings 16:6
6 At that time Rezin king of Syria recovered Elath to Syria, and drave the Jews from Elath:a and the Syrians came to Elath, and dwelt there unto this day.