"The descendants of the exiles, who are the army of the people of Israel" or 2) "this army" is a metaphor for a multitude. Alternate translation: "The descendants of the multitude of the people of Israel who were taken into exile"
Zarephath was a Phoenician city north of Israel on the coast of the Mediterranean between Tyre and Sidon. Alternate translation: "as far north as Zarephath"
This group is contrasted with either the descendants of the Israelites from the northern kingdom, or with the descendants of the people of Judah who lived outside of Jerusalem.