Whoso privily slandereth his neighbour - literally, “One who speaks concerning his neighbor in secret.” If a man has any good to say of another, he will be likely to say it openly; if he has any evil to say, it will be likely to be said in secret. Hence, to speak in secret of anyone comes to mean the same thing as to slander him.
Him will I cut off - That is, I will cut him off from me; I will not employ him. He would not have one in his house, or in his service, who did injustice to the character of others; who stabbed their reputation in the dark. This was alike indicative of the personal character of the author of the psalm, and of his purpose as the head of a family. It is hardly necessary to say that no one should employ another who is in the habit of slandering his neighbor.
Him that hath an high look - That is proud - as a proud man commonly carries his head high.
And a proud heart - The Hebrew word here rendered “proud” commonly means wide, broad, large, as of the sea, or of an extended country, Job 11:9; Exodus 3:8. It is applied also to the law of God as comprehensive, and without limit, Psalms 119:96. Then it comes to mean swelled up - made large - inflated Proverbs 28:25; and hence, proud and arrogant.
Will not I suffer - I will not tolerate such a person near me. No one can have peace in his house who has such a class of servants or domestics; no one should countenance such persons. Humility is the very foundation of all virtue.