John Calvin Commentary Isaiah 31:2

"Yet he also is wise, and will bring evil, and will not call back his words, but will arise against the house of the evil-doers, and against the help of them that work iniquity." — Isaiah 31:2 (ASV)

Yet he also is wise. By calling God “wise,” he does not merely attribute to Him the honor of an attribute that always belongs to Him, but censures the craftiness of those who he saw were too delighted with their own wisdom. He said a little before (Isaiah 29:15) that they “dug caves for themselves” when they thought that, by hidden plans and secret contrivances, they avoided and deceived the eyes of God. He now pours witty ridicule on this madness by affirming that, on the other hand, wisdom also belongs to God, indirectly charging them with believing that they could shut God’s mouth, as if He did not know their affairs. As if he had said, “What will become of your wisdom? Will its effect be that God will cease to be ‘wise’?” On the contrary, by reproving your vanity, He will give a practical demonstration that He taketh the wise in their own craftiness (Job 5:13; 1 Corinthians 3:19).

We may draw from this a general doctrine: those who shelter themselves under craftiness and secret contrivances gain nothing but to provoke God’s wrath even more. A bad conscience always flees from God’s judgment and seeks hiding places to conceal itself. Wicked men contrive various methods of guarding and fortifying themselves against God and think that they are wise and circumspect, even though they are covered only with empty masks; while others, blinded by their elevated rank, despise God and His threatenings. Thus, by declaring that “God is also wise,” the Prophet wounds them painfully and sharply, so that they may not claim such great craftiness as to be capable of deceiving God with their delusions.

He will arise against the house of the evil-doers. Since they did not deserve for Him to reason with them, He threatens that they will feel that God has His arguments at His command to ensnare transgressors. First, they did not think that God has sufficient foresight, because He did not, according to the ordinary practice of the world, provide for their safety amidst such great dangers, and because they considered all threatenings to be empty bugbears, as if they had it in their power by some means to guard against them. Hence arises their eagerness to make every exertion and their boldness to plot contrivances. He therefore threatens that God will take revenge for such a gross insult, and that He has at His command the means of executing what He has promised, and that no schemes, inventions, or craftiness can overthrow the word of God.

Of the workers of vanity. He gives them this name because they wished to fortify themselves against God’s hand by a useless defense—that is, by the unlawful aid of the Egyptians. Previously, it might be thought that he silently admitted their claim to the name “wise men” by contrasting them with God’s wisdom; but now he scatters the smoke and openly displays their shame and disgrace. This teaches us that there is nothing better than to renounce our own judgment and submit entirely to God, because all that earnest caution by which wicked men torture themselves has no solidity but, on the contrary, as if on purpose, provokes God’s wrath by the deceitful contrivances of the flesh.