Charles Ellicott Commentary Psalms 48:8

"As we have heard, so have we seen In the city of Jehovah of hosts, in the city of our God: God will establish it for ever. Selah" — Psalms 48:8 (ASV)

As we have heard. —The generations of a religious nation are “bound each to each by natural piety.” Probably here the ancient tale of the overthrow of Pharaoh and his host recurred to the poet’s mind.

God will establish it. —Better, God will preserve her for ever, i.e., the holy city. This forms the refrain of the song, and probably should be restored between the parts of Psalms 48:3.