Glorious things are ascribed to you, O city of God. Selah
PSALM 87 A Psalm or Song of the sons of Korah. It is evident, from constant observation, that, so long as the children of this world are in prosperity, they are well satisfied with their condition, and mightily extol it, while they look upon the Church with proud contempt; and even after having endured calamities, they are not so subdued by them as to renounce...
Commenting on Psalm 87:1-7
Glorious things are spoken of thee, O city of God. This is true of Jerusalem. Her history, which is the story of the nation of which she is the capital, is full of glorious incidents, and her use and end as the abode of the true God, and of his worship, was preeminently glorious. Glorious things were taught in the streets, and seen in her temples.
Some make the first words of the psalm to be part of the title; it is a psalm or song whose subject is the holy mountains - the temple built in Zion upon Mount Moriah. This is the foundation of the argument, or beginning of the psalm.
Commenting on Psalm 87:1-3