Matthew Henry on Isaiah 54:6-10

As God is slow to anger, so he is swift to show mercy. And how sweet the returns of mercy would be, when God should come and comfort them! He will have mercy on them. God's gathering his people takes rise from his mercy, not any merit of theirs; and it is with great mercies, with everlasting kindness. The wrath is little, the mercies great; the wrath for a moment, the kindness everlasting. We are neither to despond under afflictions, nor to despair of relief. Mountains have been shaken and removed, but the promises of God never were broken by any event. Mountains and hills also signify great men. Creature-confidences shall fail; but when our friends fail us, our God does not. All this is alike applicable to the church at large, and to each believer. God will rebuke and correct his people for sins; but he will not cast them off. Let this encourage us to give the more diligence to make our calling and election sure.