Charles Ellicott Commentary Psalms 47:9

"The princes of the peoples are gathered together [To be] the people of the God of Abraham: For the shields of the earth belong unto God; He is greatly exalted." — Psalms 47:9 (ASV)

The shields of the earth — that is, the princes just mentioned, as in Hosea 4:18; the Septuagint and Vulgate also render it as “strong ones,” which, however, they make the subject of the verb—“have been mightily exalted.”