Charles Ellicott Commentary Psalms 87:6

"Jehovah will count, when he writeth up the peoples, This one was born there. Selah" — Psalms 87:6 (ASV)

The proud boast of the preceding verse is repeated here with allusion to the census or birth-register of citizens. (Isaiah 4:3; Psalms 69:28, and refer to the Note.) No doubt these lists were often produced or appealed to in triumph to mark the superiority of a native of Jerusalem over those born at a distance.