The foolish man shall not know them. This is added with propriety, to let us know that the fault lies with ourselves, in not praising the Divine judgments as we ought. For although the Psalmist had spoken of them as deep and mysterious, he here informs us that they would be discerned without difficulty, were it not for our stupidity and indifference. By the foolish, he means unbelievers in general, tacitly contrasting them with believers who are divinely enlightened by the word and Spirit. The ignorance and blindness to which he alludes have possession of all without exception, whose understandings have not been illuminated by Divine grace. It ought to be our prayer to God, that he would purge our sight, and qualify us for meditation upon his works. In short, the Psalmist vindicates the incomprehensible wisdom of God from that contempt which proud men have often cast upon it, charging them with folly and madness in acting such a part; and he would arouse us from that insensibility which is too prevalent, to a due and serious consideration of the mysterious works of God.

A brutish man knoweth not - A man who is stupid, and who is like the beasts or brutes; that is, a man whose tastes and propensities are like the brutes, or who does not seem to act as if endowed with a rational nature. The idea evidently is, that there are many such people, and that it is not to be wondered at that they have no exalted idea of the greatness of God. As a matter of fact there are many in human form - many made in the image of God - who seem to have no more notion of God, and who see no more wisdom and goodness in his works, than the horse or the ox. Compare Isaiah 1:3.
Neither doth a fool understand this - A fool, in the sense that he has been made foolish and stupid by sin; that he does not worship and honor God. He has no right understanding in regard to the Maker and the Governor of the universe.

A brutish man knoweth not - איש בער ish baar, the human hog - the stupid bear - the boor; the man who is all flesh; in whom spirit or intellect neither seems to work nor exist. The brutish man, who never attempts to see God in his works.
Neither doth a fool understand this - כסיל kesil, the fool, is different from בער baar, the brutish man; the latter has mind, but it is buried in flesh; the former has no mind, and his stupidity is unavoidable.

A (e) brutish man knoweth not; neither doth a fool understand this.
(e) That is, the wicked do not consider God's works nor his judgments against them, and therefore most justly perish.

A brutish man knoweth not,.... The lovingkindness of the Lord, and his faithfulness, nor how to show them forth, nor his great works and deep thoughts; man was made originally far above the brute creatures, and had them all under his dominion; but, sinning, became like the beasts that perish; and is in Scripture often compared to one or other of them, as the horse, ass, &c. a brutish man is one that only knows things naturally, as brute beasts do, and in which also he corrupts himself; he is governed by sense, and not by reason, and much less by faith, which he has not; one that indulges his sensual appetite, whose god is his belly, and minds nothing but earth and earthly things; and, though he has an immortal soul, has no more care of it, and concern about it, than a beast that has none; he lives like one, without fear or shame; and in some things acts below them, and at last dies, as they do, without any thought of, or regard unto, a future state:
neither doth a fool understand this; what is before said, or else what follows in the next verse, as Jarchi and others interpret it, concerning the end and event of the prosperity of the wicked; Arama interprets it of the Gentiles not knowing this law of the land, the sabbath, and so rejected it: a "fool" is the same with the "brutish" man, one that is so, not in things natural and civil, but in things moral, spiritual, and religious.

A brutish man knoweth not--that is, God's works, so the Psalmist describes himself (Psalm 73:22) when amazed by the prosperity of the wicked, now understood and explained.

A brutish man - Who is led by sense, not by reason and faith. This - The depth of God's counsels and works.