Isaiah 54:10

For the mountains shall depart, and the hills be removed
As sometimes by earthquakes, and as they will at the last day, when the earth shall be dissolved, and all in it, things the most solid, firm, and durable: it may be understood comparatively; sooner shall these depart and be removed than the kindness and covenant of God: it may be interpreted figuratively of revolutions in kingdoms and states, and particularly of the abolition of Paganism in the times of Constantine; and which is expressed in much such language; "the heaven departed as a scroll when it is rolled together, and every mountain and island were moved out of their places", ( Revelation 6:14 ) . Kimchi observes, that mountains and hills may be interpreted of the kings of the nations; with this compare ( Revelation 6:15-17 ) : but my kindness shall not depart from thee;
the love of God to his people is an everlasting love; it always continues; it never did, nor never will depart, notwithstanding their fall in Adam, their depraved state by nature, their actual sins and transgressions, their many revoltings and backslidings; though the Lord may hide his face from them, and afflict them, still he loves them; whatever departs from them, his kindness shall not; though riches may flee away from them, friends stand aloof off from them, health may be taken away, and life itself, yet the love of God is always the same; and so, whatever providences may attend his church and interest in any period of time, he has the same paternal care for it, and kindness for his people, as ever: neither shall the covenant of my peace be removed;
the covenant of grace made with Christ and his people in him from everlasting, so called, because peace is a considerable article of it; even that peace which was upon the heart and thought of God from everlasting; the scheme of which was drawn by him; all things relating to it were settled in this covenant, as that Christ should be the Maker of it, and that it should be made by his blood; besides, peace includes all the blessings of grace which that covenant is stored with; and the covenant is the spring and source of all peace, spiritual and eternal: moreover, as this refers to Gospel times, the new covenant is here meant, and the publication of it, in which the Gospel of peace, or peace by Jesus Christ, is preached unto men; to which may be added, that one part, at least, of the sense of the passage, may be, that notwithstanding all the troubles and exercises the church of Christ should meet with from Rome Pagan or Papal, yet the promise and covenant of God, that it should enjoy peace and prosperity in the latter day, should never be made void, but should have its sure and certain accomplishment: saith the Lord, that hath mercy on thee;
for all springs from the mercy of God, and not the merits of men; and therefore the fulfilment of the covenant and promises may be depended upon.