Beautiful for situation - The word rendered “situation” - נוף nôph - means properly “elevation, height,” (Ges. Lexicon); and the idea here is, that the mountain referred to is “beautiful for elevation;” that is, it rises gracefully. The allusion here is to Jerusalem as it would appear to one approaching it, and especially as it appeared to the “kings” Psalms 48:4 who came to invest it, and who were so impressed with its marvelous beauty and strength, that they were afraid to attack it, and turned away Psalms 48:5.
The joy of the whole earth - Either the whole “land” of Palestine, or the whole world. Most probably the former is the meaning; and the idea is that, as a place of beauty and strength, and as a place where the worship of God was celebrated, and where the people of the land were accustomed to assemble, it was a source of national joy.
Is Mount Zion - The term used here would seem to denote the whole city, Jerusalem, as it often does. Mount Zion was the most conspicuous object in the city, the residence of the king, and for a long time, until the temple was built, the place where the ark reposed, and where the worship of God was celebrated, and hence, the term came to be used to denote the whole city.
On the sides of the north - That is, probably, the houses, the palaces, on the north sides of the Mount Zion. These were eminently beautiful; they struck one in approaching the city from that quarter, as impressive and grand. The natural and usual approach to the city was from the north, or the northwest. On the west was the valley of Gihon, on the south the valley of Hinnom; and on the east the valley of Jehoshaphat and of the brook Kidron; and it was only as the city was approached from the north that there would be a complete view of it; or, that was the only quarter from which it could be assailed. The “kings,” therefore Psalms 48:8, may be supposed to have approached it from that quarter; and thus approaching it, they would have a clear and impressive view of its beauty, and of the sources of its strength - of the walls, towers, and bulwarks which defended it, and of the magnificence of the buildings on Mount Zion. Dr. Thomson (Land and the Book, vol. ii., p. 476), says of the situation of Mount Zion, “What is there or was there about Zion to justify the high eulogium of David: “Beautiful for situation, the joy of the whole earth, is Mount Zion, on the sides of the north, the city of the great King?” The situation is indeed eminently adapted to be the platform of a magnificent citadel.
Rising high above the deep valley of Gihon and Hinnom on the west and south, and the scarcely less deep one of the Cheesemongers on the east, it could only be assailed from the northwest; and then “on the sides of the north” it was magnificently beautiful, and fortified by walls, towers, and bulwarks, the wonder and terror of the nations: “For the kings were assembled; they passed by together. They saw it, and so they marveled; they were troubled, and hasted away.” At the thought of it the royal psalmist again bursts forth in triumph: “Walk about Zion, and go round about her; tell the towers thereof; mark ye well her bulwarks; consider her palaces, that ye may tell it to the generation following.” Alas! her towers have long since fallen to the ground, her bulwarks have been overthrown, her palaces have crumbled to dust, and we who now walk about Zion can tell no other story than this to the generation following.” It was actually on the northern side of Mount Zion that most of the edifices of the city were erected. (Reland, Pales., p. 847.)
The city of the great King - That is, of God; the place where he has taken up his abode. Compare the notes at Psalms 46:4.