Psalms 125:2 - Joseph Benson’s Commentary on the Old and New Testaments

As the mountains are round about Jerusalem Defending it, not only from stormy winds and tempests, the force of which these mountains broke, but from the assaults of its enemies. And such a defence is God's providence to his people. His protection is round about them on every side, and is constant and persevering, from henceforth, says the psalmist, even for ever. Mountains may moulder and come to naught, and the rocks be removed out of their place, (Job 14:18,) but God's covenant with his people, with those who persevere in faith, love, and obedience, cannot be broken, nor his care of them cease, Isaiah 54:10.