For vain man - Margin, "empty." נבוב nâbûb, according to Gesenius, from the root נבב nâbab, to bore through, and then to be hollow; metaphorical, "empty," "foolish." The Septuagint, strangely enough, renders this," but man floats about with words." The Hebrew here means, manifestly, hollow, empty; then insincere and hypocritical. Zophar refers to a hollow-hearted man, who, though he was in fact like a wild ass's colt, attempted to appear mild and gentle, and to have a heart. The meaning is, that man by nature has a spirit untamed and unsubdued, and that with this, he assumes the appearance of gentleness and tenderness, and attempts to appear as if he was worthy of love and affection. God, seeing this hollow-heartedness, treats him accordingly. The reference here is to men like Job, and Zophar undoubtedly meant to say that he was hollow-hearted and insincere, and yet that he wished to appear to be a man having a heart, or, having true piety.
Would be wise - Various interpretations have been given to this expression. The most simple and obvious seems to be the true one, though I have not seen it noticed by any of the commentators. The word rendered "would be wise" (ילבב yı̂lâbēb) is from לבב lâbab, or לב lêb, meaning "heart," and the sense here, as it seems to me, is, "vain, hollow, and insincere, man would wish to seem to have a heart;" that is, would desire to appear sincere, or pious. Destitute of that truly, and false and hollow, he would nevertheless wish to appear different, and would put on the aspect of sincerity and religion. This is the most simple exposition, and this accords with the drift of the passage exactly, and expresses a sentiment which is unquestionably true. Gesenius, however, and some others render it, "but man is hollow and wanteth understanding; yea, man is born like a wild ass's colt, signifying the weakness and dullness of the human understanding in comparison with the divine wisdom." Others render it, "but the foolish man becometh wise when the wild ass's colt shall become a man," that is, never, a most forced and unnatural construction. Dr. Good renders it:
Will he then accept the hollow-hearted person?
Or shall the wild ass-colt assume the man?
Schultens and Dathe translate it:
Let then vain man be wise,
And the wild ass's colt become a man.
Though man be born - Though man by nature, or in connection with his birth, is untamed, lawless, rebellious. The wild ass is a striking image of that which is untamed and unsubdued; compare the notes at Job 39:5. Thus, Jeremiah describes it, "a wild ass used to the wilderness, that snuffeth up the wind at her pleasure," Jeremiah 2:24. Thus, it is said of Ishmael Genesis 16:12, "and he will be a wild man," אדם פרא pârâ' 'âdâm - a wild ass of a man. So Job 39:5 :
Who hath sent out the wild ass free?
Or who hath loosed the bands of the wild ass?
It is not quite easy for us to understand these allusions, for with us the ass is the proverbial image of stupidity, dullness, obstinacy, and immobility. But it was not so with the ancients. It is mentioned as distinguished for velocity, for wildness, and for an unsubdued spirit. Thus, Oppian, as quoted by Bochart, Hieroz. Lib. i. c. ix. p. 63, says:
Κῤαιπνὸν, ἀελλοπόδην, κρατερώνυχον, ὀξύτατον Θεῖν.
Kraipnon, aellopodēn, kraterōnuchon, ocutaton thein.
"Swift, rapid, with strong hoofs, and most fleet in his course."
And Aristotle mentions wild asses as τήν ταχυτῆτα διαφέροντες tēn tachutēta diapherontes, Hist. Lib. vi. 6 c. 36. So Aelian says of them, ὤκιστοι δραμεῖν ōkistoi dramein, fleet in their course. And Xenophon says of them, πολὺ τοῦ ἵππου θᾶττον ἔτρεχον polu tou hippou thatton etrechon, they run much swifter than a horse. In describing the march of the younger Cyrus through Syria, he says, "The wild ass, being swifter of foot than our horses, would, in gaining ground upon them, stand still and look around; and when their pursuers got nearly up to them, they would start off, and repeat the same trick; so that there remained to the hunters no other method of taking them but by dividing themselves into dispersed parties which succeeded each other in the chase;" compare Bochart, Hieroz. P. I. Lib. iii. c. xvi. pp. 867-879. A similar statement is made by Aelian (Lib. xiv. cap. 10, as quoted by Bochart), "The wild asses of Maurusius ὄνοι Μανρούσιοι onoi Maurousioi are most fleet in their course, and at the commencement of their course they seem to be borne along by the winds, or as on the wings of a bird." "In Persia," says the Editor of the Pictorial Bible, "the wild ass is prized above all other animals as an object of chase, not only from its fleetness, but the delicacy of its flesh, which made it an article of luxury even at the royal tables."
"They are now most abundantly found in the deserts of Tartary, and of the countries between the Tigris and the Indus, more particularly in the central parts of the regions thus defined. We know that they were also anciently found in the regions of Mesopotamia, Asia Minor, Syria, and Arabia Deserta; but from these regions they seem to have been, in the course of ages, almost entirely expelled or extirpated." Pict. Bib. on Job 39:5. The idea in the passage before us is, that man at his birth has a strong resemblance to a wild and untamed animal; and the passage undoubtedly indicates the early belief of the native proneness of man to wander away from God, and of his possessing by nature an insubmissive spirit.

For vain man would be wise - The original is difficult and uncertain, ואיש נבוב ילבב veish nabub yillabeb, "And shall the hollow man assume courage," or "pride himself?" Or, as Mr. Good rather paraphrases it, Will he then accept the hollow-hearted person? The Chaldee gives two renderings: An eloquent man shall become wiser in his heart, and the colt of the wild ass is born as the son of man. Or, The wise man shall ponder it; and the refractory youth, who at last becomes prudent, shall make a great man. Coverdale - A vayne body exalteth him self; and the son of man is like a wylde asse's foale. Houbigant translates thus: - A man who hath understanding will become prudent; but he who is as the wild ass hath no heart, i.e., sense. According to this critic, the meaning is this: - A man of sense, should he at any time transgress, will learn wisdom from it; but a man of a brutish mind, uncultivated and unreflecting, will plunge yet deeper into iniquity.
Though man be born like a wild ass's colt - Is translated by Mr. Good, Or shall the wild ass colt assume the man? This is making a sense, but such as I fear the original will never allow. There is no end to the translations of this verse, and conjectures relative to its meaning. I shall conclude with the Vulgate - Vir vanus in superbiam erigitur, et tanquam pullum onagri se liberum natum putat, "Vain man is puffed up with pride; and he supposes himself to be born free like the wild ass's colt." Man is full of self-conceit; and imagines himself born to act as he pleases, to roam at large, to be under no control, and to be accountable to none for his actions.

For vain man would be wise, though man be born [like] a wild (f) ass's colt.
(f) That is, without understanding, so that whatever gifts he has afterward come from God, and not from nature.

For vain man would be wise,.... Or "hollow" (r), empty man; empty of all that is good, though full of all unrighteousness; without God, the knowledge, love, and fear of him; without Christ, the knowledge of him, faith in him, and love to him; destitute of the Spirit, and of his grace, having no good thing in him: yet such a man "would be wise"; not desirous of true wisdom, but would be thought to be wise; he in conceit thinks himself that he is very wise, and he would fain have others think so of him; or is, or "may", or "will be wise" (s); may be made wise by the chastisements of God through afflictions, being sanctified to him by the grace of God; though he is a vain man, and also is what is after said of him; afflicting dispensations are sometimes teaching ones, and in the school of afflictions many useful lessons are learnt, whereby men become wiser; see Psalm 94:12; though some understand the word in a very different sense, and interpret it bold, audacious, proud, and haughty; man takes heart (t), and lifts up himself against God, stretches his hand, and hardens his heart against him:
though man be born like a wild ass's colt; foolish and stupid, without understanding of divine and spiritual things; given to lust and wantonness, to serve divers lusts and pleasures; not subject to the yoke of the law of God, stubborn, refractory, and untameable, but by the grace of God; the ass, and especially the wild ass, and the colt of one, being a very stupid creature, and a very lustful and wanton one, chooses to be free, will not bear the yoke, but ranges about in desert places; see Job 39:5; some render the words, "and a wild ass's colt is", or "may be born a man" (u); that is, one that is by his first birth, and by his life and conversation, like a wild ass's colt, is or may be born again, and be made a new man, as Jarchi also interprets it, and so become a wise, knowing, and good man, which is a great truth; but whether the truth in this text, is not so clear: the Targum seems to incline this way;"a refractory, youth that grows wise shall become a great man.''
(r) "concavus", Montanus; "cavus", Drusius; "vacuus", Pagninus, Beza, Junius & Tremellius, Piscator, Michaelis. (s) "fiat vel fit cordatus", Junius & Tremellius, Piscator; so Broughton, Beza. (t) "In superbiam erigitur", V. L. "audaciam sumit", Schmidt. (u) "Pullus onager homo nascitur", Cocceius, Schmidt; "nascatur", Schultens.

vain--hollow.
would be--"wants to consider himself wise"; opposed to God's "wisdom" (see on Job 11:11); refuses to see sin, where God sees it (Romans 1:22).
wild ass's colt--a proverb for untamed wildness (Job 39:5, Job 39:8; Jeremiah 2:24; Genesis 16:12; Hebrew, "a wild-ass man"). Man wishes to appear wisely obedient to his Lord, whereas he is, from his birth, unsubdued in spirit.

Man - That since the fall is void of all true wisdom, pretends to be wise, and able to pass a censure upon all God's ways and works. Colt - Ignorant, and dull, and stupid, as to divine things, and yet heady and untractable.