The perverse heart shall depart from me Some by perverse heart understand perfidious men; but this I reject as a sense too forced, and it is moreover inconsistent with the context. As David has added in the second clause by way of exposition, I will not know evil, he doubtless in the first protests that he will be free from all perfidiousness and wickedness. The amount is, that he will do his endeavor to keep himself from all wrong-doing, and that he will not even know what it is to do wrong to his neighbors.

A froward heart shall depart from me - The word here rendered froward means perverse, false, deceitful, depraved. See the notes at Psalm 18:26. The "idea" here is that of one who is inclined to evil; who has some wrong passion or inclination to indulge; who has an obstinate and perverse will; who does not listen to reason or the voice of wise persuasion; who will do wrong, despite all the means which may be employed to induce him to do right. The language may either refer to the author of the psalm himself, as regulating his own conduct; or it may refer to those in his employ. In the former sense, it would mean that he would not himself be perverse and froward; in the latter sense, that he would not have such persons in his employ. The connection seems to require that we should understand it in the latter sense, as referring to the class of persons that the psalmist would have about him.
I will not know a wicked person - I will not countenance such a one; I will not recognize such a one among those who are admitted into my house, or own him as my friend; or, I will not have such in my employ. Probably the language embraces both these ideas - as it should in the case of all who are at the head of a family:
(a) I will not countenance or recognize as among my friends, who are to be admitted to my fireside and family, and who are to be familiar with me and my children, those who are profligate, wicked, and unprincipled, whatever may be their rank, their wealth, their accomplishments, their fascination of manner, or their power of conversation;
(b) I will have in my employ no one who is not honest, temperate, virtuous, pure. The welfare of a family depends more on the former of these things than the latter; no family can be well ordered where both are not found.

A froward heart - Rash and headstrong men shall not be employed by me.
I will not know a wicked person - I will give no countenance to sinners of any kind; and whatever is evil shall be an object of my abhorrence.

A froward heart shall depart from me,.... A man of a froward heart, that devises frowardness in his heart, and speaks it out with his mouth; that which is perverse, and contrary to the law of God and Gospel of Christ, to the light of nature and the word of God; contrary to the sentiments of all good men, and repugnant to truth and good manners: such sort of persons are disagreeable companions, and good men would not choose to have anything to do with them; they are hateful to Christ, and shall be bid to depart from him; see Proverbs 8:13.
I will not know a wicked person: so as to be familiar with him, or show him any respect; have any affection for him, or take any notice of him; such Christ will not know at the great day, Matthew 7:23, or "I will not know wickedness" (l), or any wicked work and action, approve of it, love it, delight in it, and do it: the Targum interprets it of the evil concupiscence, corruption of nature, or indwelling sin, which is hated by the believer, Romans 7:15 and is utterly unknown to Christ; he was not conscious of it; he knew no sin, 2-Corinthians 5:21 original or actual; he had no sin in him, nor was any done by him, or, it may be, mention is made of the morning, because that was the usual time of hearing and judging causes, Jeremiah 21:12, or this may have respect to the spiritual reign of Christ, whose coming will be as the morning; when the Heathens shall perish out of his land, when sinners shall be consumed out of the earth, and the wicked shall be no more, and he will destroy them that destroy the earth, Psalm 10:16. The Targum agrees with this,
"in the world to come, which is like to the light of the morning, I will destroy all the wicked of the earth:''
that I may cut off all wicked doers from the city of the Lord; from the city of Jerusalem, as the Targum and Kimchi interpret it; and it may be understood of the church of God, in the spiritual reign of Christ, into which shall enter no more the uncircumcised and the unclean; and all that offend and do iniquity shall be gathered out of it, Isaiah 52:1 or of the New Jerusalem church state, in the personal reign of Christ, into which no wicked doers will be admitted, but will remain for ever without, Revelation 21:27.
(l) "malum hominem sive opus", Gejerus, Michaelis.

A froward heart--or, "perverse heart" (Psalm 18:26). Such a temper I will not indulge, nor even know evil or wickedness.

Depart - Shall be turned out of my court. Know - Not own nor countenance.