John Calvin Commentary Isaiah 5:20

"Woe unto them that call evil good, and good evil; that put darkness for light, and light for darkness; that put bitter for sweet, and sweet for bitter!" — Isaiah 5:20 (ASV)

Woe to them that call evil good. Though some limit this statement to judges, yet if it is carefully examined, we will easily learn from the whole context that it is general. For, having shortly before rebuked those who cannot listen to any warnings, he now proceeds with the same rebuke. It is evident that such people always have some excuse to plead, and some way of deceiving themselves; and, therefore, there is no end to their reproachful language when their crimes are brought to light. But here he particularly rebukes the insolence of those who endeavor to overthrow all distinction between good and evil.

The preposition ל (lamed), prefixed to the words good and evil, is equivalent to Of; and therefore the meaning is, They who say of evil, It is good, and of good, It is evil. That is, they who by vain hypocrisy conceal, excuse, and disguise wicked actions, as if they would change the nature of everything by their sophistical arguments, but who, on the contrary, defame good actions by their slander. These things are almost always joined together, for everyone in whom the fear of God dwells is restrained both by conscience and by modesty from venturing to apologize for his sins, or to condemn what is good and right. But those who do not have this fear do not hesitate with the same impudence to commend what is bad and to condemn what is good, which is a proof of desperate wickedness.

This statement may be applied to various cases. For if a woe is here pronounced even on private individuals when they say of evil that it is good, and of good that it is evil, how much more so on those who have been raised to any elevated rank and discharge a public office, whose duty it is to defend what is right and honorable! But he addresses a general rebuke to all who flatter themselves in what is evil, and who, through the hatred they have for virtue, condemn what is done rightly. And not only so, but who, by the subterfuges they employ for the sake of concealing their own enormities, harden themselves in wickedness. Such persons, the Prophet tells us, act as if they would change light into darkness, and sweet into bitter; by which he means that their folly is monstrous, for it would tend to confuse and destroy all the principles of nature.