John Gills Exposition of the Bible Commentary - Psalms 87:3
Glorious things are spoken of thee, O city of God. Which is to be understood not of the city of Jerusalem literally, which was a magnificent city, compact together, full of inhabitants, and spacious houses, the metropolis of Judea, and seat of the kings of Judah; and what was most glorious of all that could be said of it, it was the city of God; and so Jarchi interprets it, the glory spoken of it is, that it is the city of God; here the temple was built, and many glorious things were in it;... read more
Matthew Henry's Complete Commentary - Psalms 87:1-3
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. Or we may suppose the psalmist had now the tabernacle or temple in view and was contemplating the glories of it, and at length he breaks out into this expression, which has reference, though not to what he had written before, yet to what he had thought of; every... read more