Charles Ellicott Commentary Psalms 125:2

"As the mountains are round about Jerusalem, So Jehovah is round about his people From this time forth and for evermore." — Psalms 125:2 (ASV)

As the mountains. —In the first verse, the stability of the faithful is compared to that of Mount Zion; here their security to that of the city surrounded by its hills. (On the geographical reference, see Dean Stanley, S. and P., pp. 174, 175.) Robinson’s description is—“The sacred city lies upon the broad and high mountain range, which is shut in by the two valleys, Jehoshaphat and Hinnom.

All the surrounding hills are higher: in the east, the Mount of Olives; on the south, the so-called Hill of Evil Counsel, which ascends from the valley of Hinnom; on the west, the ground rises gently to the border of the great wadi, as described above; while on the north the bend of a ridge which adjoins the Mount of Olives limits the view to the distance of about a mile and a half.” In Zechariah 2:4-5, the protecting care of Jehovah is likened to a wall round the city, instead of to the rampart of mountains, as here.