As the mountains are round about Jerusalem - Hebrew, "Jerusalem - the mountains are round about her." Jerusalem, except on the north, is encompassed with hills or mountains, so that although the city was built on hills - Zion, Moriah, Bezethah, Acra - it was itself surrounded by hills higher than any of these, and was, in a certain sense, in a valley. See the notes at Matthew 2:1. Compare the notes at Psalm 48:1-14.

So the Lord is round about his people ... - As Jerusalem is thus protected by the hills around, so the people of God are protected by Yahweh. He surrounds the church; he is exalted far above the church; he guards the approaches to the church; he can defend it from all its foes. Under his protection it is safe. Jerusalem, as surrounded by hills and mountains, has thus become an emblem of the church at all times; its security was an emblem of the security of all who trust in the Lord.

As the mountains are round about Jerusalem - Jerusalem, according to Sandys, was situated on a rocky mountain every way to be ascended, except a little on the north, with steep ascents and deep valleys, naturally fortified. It is surrounded with other mountains, at no great distance, as if placed in the midst of an amphitheatre; for on the east is Mount Olivet, separated from the city by the valley of Jehoshaphat, which also encompasses a part of the north; on the south, the mountain of Offiner interposed with the valley of Gehinnom; and on the west it was formerly fenced with the valley of Gihon, and the mountains adjoining. The situation was such as to be easily rendered impregnable.

The Lord is round about his people - He is above, beneath, around them; and while they keep within it, their fortress is impregnable, and they can suffer no evil.

As the mountains are round about Jerusalem,.... There was Mount Zion on the side of the north, and the mount of Olives on the east, and other mountains on the other sides of it; so that it was encompassed with them, and was naturally as well as artificially fortified. Tacitus (k) describes Jerusalem as inaccessible, walls and mountains, rocks and towers, surrounding it: and the poet Coerilus (l) makes mention of a people that spoke the Phoenician language, by whom he plainly means the Jews, ' , "that inhabited the mountains of Solyma"; which are spoken of by Homer (m), from whence, according to Tacitus (n), Jerusalem had its name: yet, as Kimchi observes, this did not hinder the enemy from taking it; wherefore the Lord is a greater security to his people;

so the Lord is round about his people, from henceforth even for ever; he encompasses them with his favour and lovingkindness as a shield; he encircles them in the arms of everlasting love; he guards them by his providence all around, and keeps a wakeful and watchful eye over them, that nothing hurts them: he keeps them, as in a garrison, by his almighty power: these are the walls that are around them, yea, he himself is a wall of fire about them, and the glory in the midst of them, Zechariah 2:5; and so he continues; he never leaves his people, nor forsakes them, but is their God and guide even unto death. The Targum is,

"the Word of the Lord is round about his people;''

Christ, the essential Word of God.

(k) Hist. l. 5. c. 11. (l) Apud Euseb. Praerar. Evangel. l. 9. c. 9. (m) Odyss. 5. v. 283. (n) Ut supra. (Hist. l. 5. c. 11.)

As the mountains are round about Jerusalem, so the LORD is round about his people from henceforth even for ever.

125:1-3 All those minds shall be truly stayed, that are stayed on God. They shall be as Mount Zion, firm as it is; a mountain supported by providence, much more as a holy mountain supported by promise. They cannot be removed from confidence in God. They abide for ever in that grace which is the earnest of their everlasting continuance in glory. Committing themselves to God, they shall be safe from their enemies. Even mountains may moulder and come to nothing, and rocks be removed, but God's covenant with his people cannot be broken, nor his care of them cease. Their troubles shall last no longer than their strength will bear them up under them. The rod of the wicked may come, may fall upon the righteous, upon their persons, their estates, their liberties, their families names, on any thing that falls to their lot; only it cannot reach their souls. And though it may come upon their lot, it shall not rest thereon. The Lord will make all work together for their good. The wicked shall only prove a correcting rod, not a destroying sword; even this rod shall not remain upon them, lest they distrust the promise, thinking God has cast them off.