The Weakness of Men

Having proclaimed in Isaiah 40:1–5 the willingness of God to forgive and His return to Zion after the exile, the prophet in today’s passage contrasts the state of the Lord’s people with their Creator (vv. 6–11). He has already shown that the Lord is mighty to save and will cause His glory to be seen the world over (v. 5). However, Gentile nations and the children of Jacob are weak, and their only hope of salvation is to trust in God. Isaiah depicts the weakness of people by comparing them to grass. The voice in the wilderness calls out to the prophet to cry, and he asks the voice what his message must be. This voice responds by calling Isaiah to declare that “all flesh is grass, and all its beauty is like the flower of the field” (v. 6). The image here is one of impermanence. Grass and flowers typically grow for a season before they wither away. This is what human beings are like—we flourish for a few decades and then we are gone, but history marches on. Such withering and fading occur under the sovereignty of God. He blows, and the plants are gone. The imagery here is likely based on the hamsin, a hot east wind that occurs each May and can turn the grass from green to brown in a matter of hours. These words give two messages to the post-exilic community. First, the people of Israel and Judah must recognize their weakness, that they have no strength in themselves to provide a lasting salvation. Second, Israel and Judah must not trust earthly powers for redemption, for as strong as they may be, they are likewise but grass and flowers. Instead, God’s people must trust Him alone. Verse 8 confirms this: although grass and flowers wither and fade, the word of the Lord “will stand forever.” God’s promises are sure, permanent, and dependable, but mere mortals are not (Ps. 118:8–9; Isa. 26:4). Our trust is to be in these promises alone for salvation, for as we trust in the Lord’s Word, we are actually trusting in Him. Matthew Henry describes this trust: “We must be convinced that the word of the Lord can do that for us which all flesh cannot.” In Isaiah 40:9–11, the prophet calls for those who have recognized their need for the Lord to join His plan for the world. They are to go up on high mountains and proclaim the coming of the Lord. They are to declare that God is a shepherd—a guide and protector— to those who love Him. In short, they are to take His Word to the rest of the covenant community and, finally, the whole world (Isa. 52:7; Rom. 10:14–15).