He putteth forth his hand - That is, the miner in securing the precious metals and gems.
Upon the rock - Margin, "flint." The word used here (חלמישׁ challâmı̂ysh) occurs also in Psalm 104:8. Deuteronomy 8:15; Deuteronomy 32:13. It means "flint, silex;" and the idea is, that the miner approaches the hardest substances. He penetrates even the flint in searching for precious stones. Dr. Good renders it, "Sparry ore." Michaelis renders the same word in Deuteronomy 7:15, porphyry, or red granite. The idea is that nothing, however difficult, not even cutting down the hardest rocks, deters the miner from pursuing his work.
He overturneth the mountains by the roots - That is, he digs under them, and they fall. The root of a mountain means its base or foundation. The following passage from Pliny (Hist. Nat. xxxiii. c. iv. 21) furnishes an admirable illustration of this passage: Tamen in silice facilior existimatur labor. Esther namque terra ex quodam argillae genere glarae mixta, Candidam vocant, prope inexpugnabilis. Cuneis earn ferreis aggrediuntur, et iisdem mallets; nihilque durius putant, nisi quod inter omnia auri lama durissima est. Peracto opere cervices fornicum ab ultimo caedunt, dantque signun ruinrae, eamque solus intelligit in cacumine montis pervigil. Hic voce, ictuque, repente operarios revocari jubet, pariterque ipse devolat. Mons fractus cadit in scse Iongo fragore, qui concipi humana mente non possit, et flatu incredibili. Spectant victores ruinam naturae.

He putteth forth his hand upon the rock, - Still there appears to be a reference to mining. Man puts his hand upon the rock, he breaks that to pieces, in order to extract the metals which it contains.
He overturneth the mountains - He excavates, undermines, or digs them away, when in search of the metals contained in them: this is not only poetically, but literally, the case in many instances.

He putteth forth his hand upon the (g) rock; he overturneth the mountains by the roots.
(g) After he has declared the wisdom of God in the secrets of nature he describes his power.

He putteth forth his hand upon the rock,.... The discourse is carried on concerning the miner, and digger in the earth for metals and precious stones; who meeting with a rock or flint, and a ridge of them, is not discouraged, but goes to work therewith, and with his hammer in his hand lays upon the rock or flint, and beats it to pieces, and with proper instruments cuts through it; and using fire and vinegar, as Pliny (g) observes, makes his way into it, and oftentimes by splitting it discovers gold (h) or silver, or precious stones, in it:
he overturneth the mountains by the roots; or turns them up from the roots; he roots them up, he undermines them; he turns up the earth at the roots of them, to get what is hid at the bottom, or in the bowels of them. Some understand this, and what is said in the following verses, of God, and of wonderful things done by him; so Jarchi, Aben Ezra, and others; and to whom indeed such things are sometimes ascribed in Scripture: he touches the hills, and they smoke, Psalm 104:32; lays his hand on the rock, and removes it out of its place, Job 14:18; it was he that smote and opened the rock at Horeb, and the waters gushed out, Exodus 17:6; yea, turned the rock into standing water, and the flint into a fountain of water, Psalm 114:8, and he, in a figurative sense, has laid his hand on the rock Christ, and smote him with the rod of justice, whereby the blessings of grace come flowing down upon his people; and he it is that puts forth his hand of powerful and efficacious grace upon the rocky hearts of men, and with the hammer of his word breaks them to pieces, Jeremiah 23:29, and takes away the stony heart, and gives an heart of flesh, Ezekiel 11:19, and he also, in a literal sense, overturns hills and mountains by their roots, through storms, and tempests, and earthquakes; and figuratively, kingdoms and states, that lie in the way of his interest; for what are these mountains before the great Zerubbabel? they soon and easily become a plain; and so breaks through all difficulties, which proverbially may be signified by removing mountains, that seem to obstruct and hinder the conversion and salvation of his people; he makes those mountains a way, and his highways are exalted; see Song 2:8; but the former sense is best, and most agreeable to the context.
(g) Nat. Hist. l. 33. c. 4. "----Montem rumpit aceto", Juvenal. Sat. 10. v. 153. (h) lbid.

rock--flint. He puts forth his hand to cleave the hardest rock.
by the roots--from their foundations, by undermining them.

9 He layeth his hand upon the pebbles;
He turneth up the mountains from the root.
10 He cutteth canals through the rocks;
And his eye seeth all kinds of precious things.
11 That they may not leak, he dammeth up rivers;
And that which is hidden he bringeth to light.
12 But wisdom, whence is it obtained?
And where is the place of understanding?
Beneath, whither no other being of the upper world penetrates, man puts his hand upon the quartz or rock. חלּמישׁ (perhaps from חלם, to be strong, firm: Arabic, with the reduplication resolved, chalnubûs, like עכּבישׁ, Arab. ‛ancabûth, vid., Jesurun, p. 229) signifies here the quartz, and in general the hard stone; שׁלח יד בּ something like our "to take in hand" of an undertaking requiring strong determination and courage, which here consists in blasting and clearing away the rock that contains no ore, as Pliny, h. n. xxxiii. 4, 21, describes it: Occursant silices; hos igne et aceto rumpunt, saepius vero, quoniam id cuniculos vapore et fumo strangulat, caedunt fractariis CL libras ferri habentibus egeruntque umeris noctibus ac diebus per tenebras proxumis tradentes; lucem novissimi cernunt. Further: he (man, devoted to mining) overturns (subvertit according to the primary signification of הפך, Arab. 'fk, 'ft, to turn, twist) mountains from the roots. The accentuation הפך with Rebia mugrasch, משׁרשׁ with Mercha, is false; it is, according to Codd. and old editions, to be accented הפך with Tarcha, משׁרשׁ with Munach, and to be translated accordingly: subvertit a radice montes (for Munach is the transformation of a Rebia mugrasch), not a radice montium. Blasting in mining which lays bare the roots (the lowest parts) of the mountains is intended, the conclusion of which - the signal for the flight of the workmen, and the effective crash - is so graphically described by Pliny in the passage cited above: Peracto opere cervices fornicum ab ultumo cadunt; dat signum ruina eamque solus intellegit in cacumine ejus montis vigil. Hic voce, nutu evocari jubet operas pariterque ipse devolat. Mons fractus cadit ab sese longe fragore qui concipi humana mente non possit eque efflatu incredibili spectant victores ruinam naturae.
The meaning of Job 28:10 depends upon the signification of the יארים. It is certainly the most natural that it should signify canals. The word is Egyptian; aur in the language of the hieroglyphs signifies a river, and especially the Nile; wherefore at the close of the Laterculus of Eratosthenes the name of the king, Φρουορῶ (Φουορῶ), is explained by ἤτοι Νεῖλος. If water-canals are intended, they may be either such as go in or come away. In the first case it may mean water let in like a cataract over the ruins of the blasted auriferous rock, the corrugi of Pliny: Alius par labor ac vel majoris impendi: flumina ad lavandam hanc ruinam jugis montium obiter duxere a centesimo plerumque lapide; corrugos vocant, a corrivatione credo; mille et hic labores. But בּקּע is not a suitable word for such an extensive and powerful flooding with water for the purpose of washing the gold. It suits far better to understand the expression of galleries or ways cut horizontally in the rock to carry the water away. Thus von Veltheim explains it: "The miner makes ways through the hard rock into his section in which the perpendicular shaft terminates, guides the water which is found in abundance at that depth through it [i.e., the water as the bottom of the pit that hinders the progress of the work], and is able [thus Job 28:10 naturally is connected with what precedes] to judge of the ore and fragments that are at the bottom, and bring them to the light. This mode of mining by constantly forming one gallery under the other [so that a new gallery is made under the pit that is worked out by extending the shaft, and also freeing this from water by making another outlet below the previous one] is the oldest of all, of which anything certain is known in the history of mining, and the most natural in the days when they had no notion of hydraulics." This explanation is far more satisfactory than that of Herm. Sam. Reimarus, of the "Wolfenbtteler Fragmente" (in his edition of the Neue Erkl. des B. Hiob, by John Ad. Hoffmann, 1734, iv. S. 772): "He breaks open watercourses in the rocks. What the miners call coming upon water, is when they break into a fissure from which strong streams of water gush forth. The miner not only knows how to turn such water to good account, but it is also a sign that there are rich veins of ore near at hand, as there is the most water by these courses and fissures. Hence follows: and then his eye sees all kinds of precious things." But there is no ground for saying that water indicates rich veins of ore, and בקע is much more appropriate to describe the designed formation of courses to carry off the water than an accidental discovery of water in course of the work; moreover, יארים is as appropriate to the former as it is inappropriate to the latter explanation, for it signifies elsewhere the arms of the Nile, into which the Nile is artificially divided; and therefore it may easily be transferred to the horizontal canals of the mine cut through the hard rock (or through the upper earth). Nevertheless, although the water plays an important part in mining operations, by giving rise to the greatest difficulties, as it frequently happens that a pit is deluged with water, and must be abandoned because no one can get down to it: it is improbable that Job 28:10 as well as Job 28:11 refers to this; we therefore prefer to understand יארים as meaning the (horizontal) courses (galleries or drifts) in which the ore is dug, - a rendering which is all the more possible, since, on the one hand, in Coptic jaro (Sahidic jero) signifies the Nile of Egypt (phiaro ente chêmi); on the other, ior (eioor) signifies a ditch, διώρυξ (comp. Isaiah 33:21, יארים, lxx διώρυχες), vid., Ges. Thes. Thus also Job 28:10 is consistently connected with what precedes, since by cutting these cuniculi the courses of the ore (veins), and any precious stones that may also be embedded there, are laid bare.

He, &c. - This and the two next verses mention other eminent works of God, who overturneth rocks, and produceth new rivers.