Read this chapter in light of both its beginning and its ending. It ends with God delivering “Jacob”/Israel to utter destruction and reviling (28). And yet the chapter begins with God’s loving, affectionate promise to gather back His scattered people (1-7). How can God do both?
Once destroyed, the old Israel may be safely forgotten (18), because God is doing a “new thing” (19). It is not “new” in the sense that we would say something is “brand new”, “out of thin air.” It is “new” in the sense that we say there’s a “new moon.” It’s still the same moon, but now operating in a different phase. Thus He will lead His people on a new exodus (16-17). As they walk in the wilderness of this world, He will lead them on the way (19b), giving them living water (20). God does this because of His own sovereign choice (20), not because they earned this favor.
And as with the “old” Israel, so with this “new” Israel: He forms this people for Himself, “that they might declare my praise” (21). Thus God both judges and redeems. He judges the wearisome sin of His chosen people (22-24), and yet He blots out their transgressions, that He might not remember their sins (25). In fact, God redeems through the judgment. He gave up nations for them (4, 14-15). And He will even give up His own people to judgment (28), that He might create Israel anew.
Thus will He judge His own Son, on behalf of Israel, to redeem Israel. Reflect well on verses 10-11.