The following is from John Calvin’s commentary on Isaiah 14.
It will be asked, Was there a period during which God had no compassion? Undoubtedly, he always had compassion; but while the people were distressed by heavy calamities, it was not perceived; for, having their minds previously occupied with a view of God’s anger, and, judging from outward appearances, they could not perceive God’s compassion. Yet the Lord was always like himself, and never laid aside his nature. Thus it is proper to distinguish between the knowledge which springs from faith and the knowledge which springs from experience; for when the tokens of God’s anger are visible all around, and when the judgment of the flesh leads us to believe that he is angry, his favor is concealed from us; but faith raises our hearts above this darkness, to behold God in heaven as reconciled towards us. What follows is somewhat more startling.
And will yet choose Israel, or, will again choose Israel. God’s election is eternal. He does not choose us as if this had never before come into his mind; and as we were chosen before the foundation of the world, (Ephesians 1:4,) so he never repents of his choice. (Romans 11:29.) But when the Lord chastises his people, this has the appearance of rejecting them; as we learn from the frequent complaints of the saints, Lord, why hast thou cast us off? (Psalm 74:1.) We look at God’s rejection or election according to our weakness, and judge of his feelings toward us by the outward action. (I speak of the knowledge which is derived from experience, and which is corrected by the light of faith.) Accordingly, when the Lord calls us, that is, confirms his election, he is said to choose us; and when he gives evidence that he is displeased, he is said to reject us. The meaning, therefore, is, “Though the Lord has treated his people so severely, as if he had rejected them; yet by the actual event he will at length show and prove that he has adopted them, by giving abundant evidence of his election, and by having compassion on them for ever.” [source]