28 Have you never heard? Have you never understood? The Lord is the everlasting God, the Creator of all the earth. He never grows weak or weary. No one can measure the depths of his understanding. 29 He gives power to the weak and strength to the powerless. 30 Even youths will become weak and tired, and young men will fall in exhaustion. 31 But those who trust in the Lord will find new strength. They will soar high on wings like eagles. They will run and not grow weary. They will walk and not faint.

Matthew Henry's Commentary on Isaiah 40:28-31

Commentary on Isaiah 40:27-31

(Read Isaiah 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.