Psalm 87 is a Psalm of Gentile inclusion. Five nations, several of them traditional enemies of Israel – Egypt, Babylon, Philistia, Tyre, and Ethiopia – are born again, given a fresh genealogy as if they were naturally born citizens of Zion. Psalm 87 is the Ephesians 2 of the Psalter (or, more accurately, one of the Ephesians 2s).
What do these reborn nations do? “Those who sing as well as those who play flues [or, those who dance] shall say, ‘All my springs are in you” (v. 7). They join Zion’s orchestra, choir, and dance company.
This is God’s purpose in history: To form a choir from every tribe and tongue, to make warring nations into dance partners.