‘Therefore ye sons of Jacob are not consumed‘, which means, you are not utterly consumed; it fits in with the previous verses. There will be a remnant of you left.
This doctrine of God unchanging faithfulness to himself and his word is a great comfort to us. We have given him ample reason to change his mind if he was going to do so. If it were anyone else we were dealing with, we would have exhausted their patience long ago. We sin, we come in repentance and sorrow, and we ask for pardon. He hears us and forgives and restores us. But then we do the same all over again. But God has set his love upon us and his unchanging love is our strength.