40:27-31 The people of God are reproved for their unbelief and distrust of God. Let them remember they took the names Jacob and Israel, from one who found God faithful to him in all his straits. And they bore these names as a people in covenant with Him. Many foolish frets, and foolish fears, would vanish before inquiry into the causes. It is bad to have evil thoughts rise in our minds, but worse to turn them into evil words. What they had known, and had heard, was sufficient to silence all these fears and distrusts. Where God had begun the work of grace, he will perfect it. He will help those who, in humble dependence on him, help themselves. As the day, so shall the strength be. In the strength of Divine grace their souls shall ascend above the world. They shall run the way of God's commandments cheerfully. Let us watch against unbelief, pride, and self-confidence. If we go forth in our own strength, we shall faint, and utterly fall; but having our hearts and our hopes in heaven, we shall be carried above all difficulties, and be enabled to lay hold of the prize of our high calling in Christ Jesus.

31. mount up—(2Sa 1:23). Rather, "They shall put forth fresh feathers as eagles" are said to renovate themselves; the parallel clause, "renew their strength," confirms this. The eagle was thought to moult and renew his feathers, and with them his strength, in old age (so the Septuagint, Vulgate, Ps 103:5). However, English Version is favored by the descending climax, mount up—run—walk; in every attitude the praying, waiting child of God is "strong in the Lord" (Ps 84:7; Mic 4:5; Heb 12:1).