Adam Clarke on Psalms 48:2

The joy of the whole earth - Commentators have been greatly puzzled to show in what sense Zion, or the temple, could be said to be the joy of the whole earth. If we take the earth here for the habitable globe, there is no sense in which it ever was the joy of the whole earth; but If we take כל הארץ col haarets, as signifying the whole of this land, (and it has no other meaning), the assertion is plain and easy to be understood, for the temple was considered the ornament and glory of the whole land of Judea.