John Calvin Commentary Isaiah 8:10

"Take counsel together, and it shall be brought to nought; speak the word, and it shall not stand: for God is with us." — Isaiah 8:10 (ASV)

Take counsel. After discussing the enemies' forces, he now addresses their counsels. It is as if he had said, “Although the enemies may abound not only in armor and strength, but also in counsel and wisdom, they will still accomplish nothing.” This warning was very necessary, because it often happens that we despise enemies—though powerful and well-armed—if they lack counsel and are guided by blind violence rather than by reason.

He therefore forewarns them that the enemies' craftiness, and all the schemes by which they try to gain an advantage over God's people, will ultimately be unsuccessful. Consequently, they will accomplish nothing, even if they lack nothing and possess a great abundance of everything: forces, counsels, and crafty designs. He adds—

Speak the word. To make the meaning clearer, I have rendered it decree a decree. This relates to their insolence, or it is the conclusion of their consultation, because a decree usually follows deliberation. He declares that all these things will vanish into smoke.

Therefore, it is clear enough what the Prophet means and how this passage should be applied. It can be regarded as a shield with which we can drive away all terrors from enemies, whether they excel in forces, wealth, power, influence, and rank on the one hand, or in wisdom, counsel, craftiness, sagacity, and invention on the other—or, in a word, in insolence. For we are well-armed and very powerful if God is with us; therefore, all the schemes or decrees of adversaries will immediately vanish.

For God is with us. כי עמנו אל (ki Immanu-el), literally, for Immanuel. We have already explained the force of this argument. Personally, I have no doubt that he alludes to the name he previously gave to Christ. For although he means that God helps His people, yet because the majesty of God is not, by itself, sufficient to support us, he contemplates God Himself in the person of the Mediator, in whom alone He has promised to help us.