III. Here is a threatening of wrath against those who hated to be reformed. As, when judgments are threatened, the righteous are distinguished so as not to share in the evil of those judgments, so, when favours are promised, the wicked are distinguished so as not to share in the comfort of those favours; they have no part nor lot in the matter, v. 21. But, as for those that have no grace, what have they to do with peace? Observe, 1. Their description. Their heart walks after the heart of their detestable things; they have as great a minds to worship devils as devils have to be worshipped. Or, in opposition to the new heart which God gives his people, which is a heart after his own heart, they have a heart after the heart of their idols; in their temper and practice they conformed to the characters and accounts given them of their idols, and the ideas they had of them, and of them they learned lewdness and cruelty. Here lies the root of all their wickedness, the corruption of the heart; as the root of their reformation is laid in the renovation of the heart. The heart has its walks, and according as those are the man is. 2. Their doom. It carries both justice and terror in it: I will recompense their way upon their own heads; I will deal with them as they deserve. There needs no more than this to speak God righteous, that he does but render to men according to their deserts: and yet such are the deserts of sin that there needs no more than this to speak the sinner miserable.