John Calvin on Isaiah 30:12

12. Because you have disdained this word. He next declares the punishment of ungodliness, threatening that they shall not pass unpunished for refusing to hear God speaking; and he expresses their contempt more strongly by the word “disdain.” He calls it “this word,” making use of the demonstrative; for men would willingly contrive some word adapted to their manner of life, but refuse to listen to God when he speaks.

And trusted in violence and wickedness. God’s gentle invitation, and his exhortation to quiet rest, are here contrasted with their disorderly pursuits. The Hebrew word עשק (gnōshĕk) denotes “robbery,” and “seizing property which belongs to another.” Others render it “ill-gotten wealth.” Those who render it “calumny,” do not sufficiently express the Prophet’s meaning. For my own part, I do not view it as referring to riches gained by unlawful methods, but rather to that rebelliousness in which that nation insolently indulged.

The word “wickedness,” {Bogus footnote} which is added, ought not to be limited to decisions of courts of law; for, in my opinion, it has a more extensive signification; and by these two words he intended to express the presumption of wicked men, by which they fiercely and wantonly rose up against God, because they always dared to follow their own lawless desires, and to do what was forbidden. And as the poets feign that the giants made war with God, {Bogus footnote} so those men resisted God’s threatenings, and thought that they would speedily overcome his power by their fierceness and presumption.