The pillars of Heaven tremble - That is, the mountains, which seem to bear up the heavens. So, among the ancients. Mount Atlas was represented as one of the pillars of heaven. Virgil speaks of "Atlas whose brawny back supports the skies." And Hesiod, ver. 785, advances the same notion:
"Atlas, so hard necessity ordains,
Great, the ponderous vault of stars sustains
Not far from the Hesperides he stands,
Nor from the load retracts his head or hands."
The word "reproof" in this verse refers to the language of God, as if spoken in anger to rebuke the mountains or the earth. Perhaps the reference is to thunder, to storms, and to winds, which seem to be the voice of God; compare Psalm 29:3-8. Similar descriptions of the majesty and glory of God abound in the Scriptures, where he speaks to the earth, the mountains, the hills, and they tremble. Thus, in Psalm 104:32;
He looketh on the earth, and it trembleth;
He toucheth the hills, and they smoke.
So in Habakkuk 3:10 :
The mountains saw thee, and they trembled;
The overflowing of the water passed by;
The deep uttered his voice, and lift up his hands on high.
So in Nahum 1:5, "The mountains quake at him, and the hills melt, and the earth is burnt at his presence."

The pillars of heaven tremble - This is probably a poetical description either of thunder, or of an earthquake: -
"He shakes creation with his nod;
Earth, sea, and heaven, confess him God."
But there may be an allusion to the high mountains, which were anciently esteemed by the common people as the pillars on which the heavens rested; and when these were shaken with earthquakes, it might be said the pillars of heaven tremble. Mount Atlas was supposed to be one of those pillars, and this gave rise to the fable of Atlas being a man who bore the heavens on his shoulders. The Greek and Roman poets frequently use this image. Thus Silius Italicus, lib. i., ver. 202: -
Atlas subducto tracturus vertice coelum:
Sidera nubiferum fulcit caput, aethereasque
Erigit aeternum compages ardua cervix:
Canet barba gelu, frontemque immanibus umbris
Pinea silva premit; vastant cava tempora venti
Nimbosoque ruunt spumantia flumina rictu.
"Atlas' broad shoulders prop th' incumbent skies:
Around his cloud-girt head the stars arise.
His towering neck supports th' ethereal way;
And o'er his brow black woods their gloom display.
Hoar is his beard; winds round his temples roar;
And from his jaws the rushing torrents pour."
J. B. C.

The (k) pillars of heaven tremble and are astonished at his reproof.
(k) Not that heaven has pillars to uphold it, but he speaks by a similitude as though he would say heaven itself is not able to abide his reproach.

The pillars of heaven tremble,.... Which may be understood either of the air, the lower part of the heavens, which may be thought to be the foundation, prop, and support of them, and is sometimes called the firmament, and "the firmament of his power", Psalm 150:1; and which seems to tremble when there are thunder and lightnings, and coruscations in it; or else the mountains, which, reaching up to the heavens, look as if they were the pillars and support of them; and are indeed said to be the foundations of heaven, which move and shake and tremble at the presence and power of God, and at any expressions of his wrath and anger, and particularly through earthquakes and storms, and tempests of thunder and lightning; see 2-Samuel 22:8, which are meant by what follows:
and are astonished at his reproof; his voice of thunder, which is sometimes awful and terrible, astonishing and surprising; and, to set forth the greatness of it, inanimate creatures are represented as trembling, and astonished at it; see Psalm 104:7; some interpret this figuratively of angels, who they suppose are employed in the direction of the heavens, and the motion of the heavenly bodies; and who they think are the same which in the New Testament are called "the powers of heaven said to be shaken", Matthew 24:29; and to be the seraphim that covered their faces upon a glorious display of the majesty of God, and when the posts of the door of the temple moved at the voice of him that cried, Isaiah 6:1; but if a figurative sense may be admitted of, the principal persons in the church, sometimes signified by heaven in Scripture, may be thought of; as ministers of the word, who are pillars in the house of God; yea, every true member of the church of God is made a pillar in it; and these tremble, and are astonished oftentimes when the Lord rebukes them by afflictions, though it is in love and kindness to them, Proverbs 9:1.

pillars--poetically for the mountains which seem to bear up the sky (Psalm 104:32).
astonished--namely, from terror. Personification.
his reproof-- (Psalm 104:7). The thunder, reverberating from cliff to cliff (Habakkuk 3:10; Nahum 1:5).

11 The pillars of heaven tremble
And are astonished at His threatening.
12 By His power He rouseth up the sea,
And by His understanding He breaketh Rahab in pieces.
13 By His breath the heavens become cheerful;
His hand hath formed the fugitive dragon.
The mountains towering up to the sky, which seem to support the vault of the sky, are called poetically "the pillars of heaven." ירופפוּ is Pulal, like יחוללוּ, Job 26:5; the signification of violent and quick motion backwards and forwards is secured to the verb רוּף by the Targ. אתרופף = התפּלּץ, Job 9:6, and the Talm. רפרף of churned milk, blinding eyes (comp. הרף עין, the twinkling of the eye, and Arab. rff, fut. i. o. nictare), flapping wings (comp. Arab. rff and rfrf, movere, motitare alas), of wavering thinking. גּערה is the divine command which looses or binds the powers of nature; the astonishment of the supports of heaven is, according to the radical signification of תּמהּ (cogn. שׁמם), to be conceived of as a torpidity which follows the divine impulse, without offering any resistance whatever. That רגע, Job 26:12, is to be understood transitively, not like Job 7:5, intransitively, is proved by the dependent (borrowed) passages, Isaiah 51:15; Jeremiah 31:35, from which it is also evident that רגע cannot with the lxx be translated κατέπαυσεν. The verb combines in itself the opposite significations of starting up, i.e., entering into an excited state, and of being startled, from which the significations of stilling (Niph., Hiph.), and of standing back or retreat (Arab. rj‛), branch off. The conjecture גּער after the Syriac version (which translates, go‛ar bejamo) is superfluous. רהב, which here also is translated by the lxx τὸ κῆτος, has been discussed already on Job 9:13. It is not meant of the turbulence of the sea, to which מחץ is not appropriate, but of a sea monster, which, like the crocodile and the dragon, are become an emblem of Pharaoh and his power, as Isaiah 51:9. has applied this primary passage: the writer of the book of Job purposely abstains from such references to the history of Israel. Without doubt, רהב denotes a demoniacal monster, like the demons that shall be destroyed at the end of the world, one of which is called by the Persians akomano, evil thought, another taromaiti, pride. This view is supported by Job 26:13, where one is not at liberty to determine the meaning by Isaiah 51:9, and to understand נחשׁ בּרח, like תּנּין in that passage, of Egypt. But this dependent passage is an important indication for the correct rendering of חללה. One thing is certain at the outset, that שׁפרה is not perf. Piel = שׁפרה, and for this reason, that the Dagesh which characterizes Piel cannot be omitted from any of the six mutae; the translation of Jerome, spiritus ejus ornavit coelos, and all similar ones, are therefore false. But it is possible to translate: "by His spirit (creative spirit) the heavens are beauty, His hand has formed the flying dragon." Thus, in the signification to bring forth (as Proverbs 25:23; Proverbs 8:24.), חללה is rendered by Rosenm., Arnh., Vaih., Welte, Renan, and others, of whom Vaih. and Renan, however, do not understand Job 26:13 of the creation of the heavens, but of their illumination. By this rendering Job 26:13 and Job 26:13 are severed, as being without connection; in general, however, the course of thought in the description does not favour the reference of the whole of half of Job 26:13 to the creation. Accordingly, חללה is not to be taken as Pilel from חול (ליל), but after Isaiah 57:9, as Poel from חלל, according to which the idea of Job 26:13 is determined, since both lines of the verse are most closely connected.
(בּריח) נחשׁ בּרח is, to wit, the constellation of the Dragon,
(Note: Ralbag, without any ground for it, understands it of the milky way (העגול החלבי), which, according to Rapoport, Pref. to Slonimski's Toledoth ha-schamajim (1838), was already known to the Talmud b. Berachoth, 58 b, under the name of נהר דנוד.)
one of the most straggling constellations, which winds itself between the Greater and Lesser Bears almost half through the polar circle.
"Maximus hic plexu sinuoso elabitur Anguis
Circum perque duas in morem fluminis Arctos."
(Virgil, Georg. i. 244f.)
Aratus in Cicero, de nat. Deorum, ii. 42, describes it more graphically, both in general, and in regard to the many stars of different magnitudes which form its body from head to tail. Among the Arabs it is called el-hajje, the serpent, e.g., in Firuzabdi: the hajje is a constellation between the Lesser Bear (farqadân, the two calves) and the Greater Bear (benât en-na‛sch, the daughters of the bier), "or et-tanı̂n, the dragon, e.g., in one of the authors quoted by Hyde on Ulugh Beigh's Tables of the Stars, p. 18: the tann lies round about the north pole in the form of a long serpent, with many bends and windings." Thus far the testimony of the old expositors is found in Rosenmller. The Hebrew name תּלי (the quiver) is perhaps to be distinguished from טלי and דּלי, the Zodiac constellations Aries and Aquarius.
(Note: Vid., Wissenschaft, Kunst, Judenthum (1838), S. 220f.)
It is questionable how בּרח is to be understood. The lxx translates δράκοντα ἀποστάτην in this passage, which is certainly incorrect, since בריח beside נחשׁ may naturally be assumed to be an attributive word referring to the motion or form of the serpent. Accordingly, Isaiah 27:1, ὄφιν φείγοντα is more correct, where the Syr. version is חויא חרמנא, the fierce serpent, which is devoid of support in the language; in the passage before us the Syr. also has חויא דערק, the fleeing serpent, but this translation does not satisfy the more neuter signification of the adjective. Aquila in Isaiah translates ὄφιν μόχλον, as Jerome translates the same passage serpentem vectem (whereas he translates coluber tortuosus in our passage), as though it were בּריח; Symm. is better, and without doubt a substantially similar thought, ὄφιν συγκλείοντα, the serpent that joins by a bolt, which agrees with the traditional Jewish explanation, for the dragon in Aben-Ezra and Kimchi (in Lex.) - after the example of the learned Babylonian teacher of astronomy, Mark-Samuel (died 257), who says of himself that the paths of the heavens are as familiar to him as the places of Nehardea
(Note: Vid., Grtz, Geschichte der Juden, iv. 324. On Isaiah 27:1 Kimchi interprets the מבריח differently: he scares (pushes away).)
- is called נחשׁ עקלתון, because it is as though it were wounded, and בריח, because it forms a bar (מבריח) from one end of the sky to the other; or as Sabbatai Donolo (about 94), the Italian astronomer,
(Note: Vid., extracts from his המזלות ספר in Joseph Kara's Comm. on Job, contributed by S. D. Luzzatto in Kerem Chemed, 7th year, S. 57ff.)
expresses it: "When God created the two lights (the sun and moon) and the five stars (planets) and the twelve מזלור (the constellations of the Zodiac), He also created the תלי (dragon), to unite these heavenly bodies as by a weaver's beam (מנור אורגים), and made it stretch itself on the firmament from one end to another as a bar (כבריח), like a wounded serpent furnished with the head and tail." By this explanation בּריח is either taken directly as בּריח, vectis, in which signification it does not, however, occur elsewhere, or the signification transversus (transversarius) is assigned to the בּריח (= barrı̂ah) with an unchangeable Kametz, - a signification which it might have, for brch Arab. brḥ signifies properly to go through, to go slanting across, of which the meanings to unite slanting and to slip away are only variations. בּריח, notwithstanding, has in the language, so far as it is preserved to us, everywhere the signification fugitivus, and we will also keep to this: the dragon in the heavens is so called, as having the appearance of fleeing and hastening away. But in what sense is it said of God, that He pierces or slays it? In Isaiah 51:9, where the תנין is the emblem of Egypt (Pharaoh), and Isaiah 27:1, where נחשׁ בריח is the emblem of Assyria, the empire of the Tigris, the idea of destruction by the sword of Jehovah is clear. The present passage is to be explained according to Job 3:8, where לויתן is only another name for נחש בריח (comp. Isaiah 27:1). It is the dragon in the heavens which produces the eclipse of the sun, by winding itself round about the sun; and God must continually wound it anew, and thus weaken it, if the sun is to be set free again. That it is God who disperses the clouds of heaven by the breath of His spirit, the representative of which in the elements is the wind, so that the azure becomes visible again; and that it is He who causes the darkening of the sun to cease, so that the earth can again rejoice in the full brightness of that great light, - these two contemplations of the almighty working of God in nature are so expressed by the poet, that he clothes the second in the mythological garb of the popular conception.
In the closing words which now follow, Job concludes his illustrative description: it must indeed, notwithstanding, come infinitely short of the reality.

Pillars - Perhaps the mountains which by their height and strength seem to reach and support the heavens. Astonished - When God reproveth not them, but men by them, manifesting his displeasure by thunders, or earthquakes.