Verse 12. - A generation that are pure in their own eyes (Proverbs 20:9). The second characteristic is hypocrisy and Pharisaical self-righteousness (see Luke 18:11). And yet are not washed from their filthiness; have not cleansed their heart by complete repentance, either because they have not examined themselves and know nothing of the real state of their conscience, or because they care nothing about it and will not regard it in its true light. There is a similar expression in Isaiah 4:4. Septuagint, "A wicked generation judgeth themselves to be just, but have not washed themselves clean (τὴν ἔξοδον αὐτοῦ οὐκ ἀπένιψεν)."

30:10 Slander not a servant to his master, accuse him not in small matters, to make mischief. 11-14. In every age there are monsters of ingratitude who ill-treat their parents. Many persuade themselves they are holy persons, whose hearts are full of sin, and who practise secret wickedness. There are others whose lofty pride is manifest. There have also been cruel monsters in every age. 15-17. Cruelty and covetousness are two daughters of the horseleech, that still cry, Give, give, and they are continually uneasy to themselves. Four things never are satisfied, to which these devourers are compared. Those are never rich that are always coveting. And many who have come to a bad end, have owned that their wicked courses began by despising their parents' authority. 18-20. Four things cannot be fully known. The kingdom of nature is full of marvels. The fourth is a mystery of iniquity; the cursed arts by which a vile seducer gains the affections of a female; and the arts which a vile woman uses to conceal her wickedness. 21-23 Four sorts of persons are very troublesome. Men of low origin and base spirit, who, getting authority, become tyrants. Foolish and violent men indulging in excesses. A woman of a contentious spirit and vicious habits. A servant who has obtained undue influence. Let those whom Providence has advanced from low beginnings, carefully watch against that sin which most easily besets them.There is a generation that are pure in their own eyes,.... Not in the eyes of God, who sees the heart, and all the impurities of it, as well as of life and conversation; nor in the eyes of others, though such may appear outwardly righteous before men; but in their own eyes, in their own conceit and imagination, trusting in themselves that they are righteous: but such have not their eyes opened or enlightened to see the plague of their own hearts, the spirituality of the law of God, the perfection of righteousness that requires; nor the righteousness and holiness of God himself; nor the imperfection and insufficiency of their own; did they, they would not seem pure and righteous to themselves. No man is pure by nature, or through anything done by them; but by the grace of God, and through the blood and righteousness of Christ; and such are far from being pure in their own eyes, or as considered in themselves: but those who are pure neither by nature nor by grace, yet think they are so. There were some such in Agur's time, and such were the Scribes and Pharisees in Christ's time; there were a generation of them; and there are of the same sort in our days, as Papists, Perfectionists, and all self-justiciaries; see Luke 18:9;

and yet is not washed from their filthiness; their native, original, and universal pollution by sin they have from their birth, and which is increased by numerous actual transgressions; and from which none are or can be washed but those who are born of water and of the Spirit, or are washed with the washing of regeneration; and are washed from their sins in the blood of the Lamb, whose blood cleanses from all sin; and are arrayed with the fine linen, clean and white, the righteousness of the saints, which is the righteousness of Christ imputed to them: whatsoever is short of these leaves men unwashed from their filthiness, whatever opinion they may have of themselves; see Job 9:30, Jeremiah 2:22.