Biblical Commentary on the Old Testament, by Carl Friedrich Keil and Franz Delitzsh, [1857-78], at sacred-texts.com
There is nothing to surprise us in the fact, that the prophet returns again and again to the alliance with Egypt. After his warning had failed to prevent it, he wrestled with it in spirit, set before himself afresh the curse which would be its certain fruit, brought out and unfolded the consolation of believers that lay hidden in the curse, and did not rest till the cursed fruit, that had become a real thing, had been swallowed up by the promise, which was equally real. The situation of this fourth woe is just the same as that of the previous one. The alliance with Egypt is still in progress. "Woe to them that go down to Egypt for help, and rely upon horses, and put their trust in chariots, that there are many of them; and in horsemen, that there is a powerful multitude of them; and do not look up to the Holy One of Israel, and do not inquire for Jehovah! And yet He also is wise; thus then He brings evil, and sets not His words aside; and rises up against the house of miscreants, and against the help of evil-doers. And Egypt is man, and not God; and its horses flesh, and not spirit. And when Jehovah stretches out His hand, the helper stumbles, and he that is helped falls, and they all perish together." The expression "them that go down" (hayyōredı̄m) does not imply that the going down was taking place just then for the first time. It is the participle of qualification, just as God is called הבּרא. לעזרה with Lamed of the object, as in Isa 20:6. The horses, chariots, and horsemen here, as those of Egypt, which Diodorus calls ἱππάσιμος, on account of its soil being so suitable for cavalry (see Lepsius in Herzog's Cyclopaedia). The participle is combined in the finite verb. Instead of ועל־סוּסים, we also find the reading preferred by Norzi, of על without Vav, as in Isa 5:11 (cf., Isa 5:23). The perfects, שׁעוּ לא and דרשׁוּ לא, are used without any definite time, to denote that which was always wanting in them. The circumstantial clause, "whilst He is assuredly also wise," i.e., will bear comparison with their wisdom and that of Egypt, is a touching μείωσις. It was not necessary to think very highly of Jehovah, in order to perceive the reprehensible and destructive character of their apostasy from Him. The fut. consec. ויּבא is used to indicate the inevitable consequence of their despising Him who is also wise. He will not set aside His threatening words, but carry them out. The house of miscreants is Judah (Isa 1:4); and the help (abstr. pro concr., just as Jehovah is frequently called "my help," ‛ezrâthı̄, by the Psalmist) of evil-doers is Egypt, whose help has been sought by Judah. The latter is "man" ('âdâm), and its horses "flesh" (bâsâr); whereas Jehovah is God (El) and spirit (rūăch; see Psychol. p. 85). Hofmann expounds it correctly: "As ruuach has life in itself, it is opposed to the bâsâr, which is only rendered living through the rūăch; and so El is opposed to the corporeal 'âdâm, who needs the spirit in order to live at all." Thus have they preferred the help of the impotent and conditioned, to the help of the almighty and all-conditioning One. Jehovah, who is God and spirit, only requires to stretch out His hand (an anthropomorphism, by the side of which we find the rule for interpreting it); and the helpers, and those who are helped (i.e., according to the terms of the treaty, though not in reality), that is to say, both the source of the help and the object of help, are all cast into one heap together.
And things of this kind would occur. "For thus hath Jehovah spoken to me, As the lion growls, and the young lion over its prey, against which a whole crowd of shepherds is called together; he is not alarmed at their cry, and does not surrender at their noise; so will Jehovah of hosts descend to the campaign against the mountain of Zion, and against their hill." There is no other passage in the book of Isaiah which sounds so Homeric as this (vid., Il. xviii. 161, 162, xii. 299ff.). It has been misunderstood by Knobel, Umbreit, Drechsler, and others, who suppose על לצבּא to refer to Jehovah's purpose to fight for Jerusalem: Jehovah, who would no more allow His city to be taken from Him, than a lion would give up a lamb that it had taken as its prey. But how could Jerusalem be compared to a lamb which a lion holds in its claws as tereph? (Isa 5:29). We may see, even from Isa 29:7, what construction is meant to be put upon על צבא. Those sinners and their protectors would first of all perish; for like a fierce indomitable lion would Jehovah advance against Jerusalem, and take it as His prey, without suffering Himself to be thwarted by the Judaeans and Egyptians, who set themselves in opposition to His army (The Assyrians). The mountain of Zion was the citadel and temple; the hill of Zion the city of Jerusalem (Isa 10:32). They would both be given up to the judgment of Jehovah, without any possibility of escape. The commentators have been misled by the fact, that a simile of a promising character follows immediately afterwards, without anything to connect the one with the other. But this abrupt μετάβασις was intended as a surprise, and was a true picture of the actual fulfilment of the prophecy; for in the moment of the greatest distress, when the actual existence of Jerusalem was in question (cf., Isa 10:33-34), the fate of Ariel took suddenly and miraculously a totally different turn (Isa 29:2). In this sense, a pleasant picture is placed side by side with the terrible one (compare Mic 5:6-7).
Jehovah suddenly arrests the work of punishment, and the love which the wrath enfolds within itself begins to appear. "Like fluttering birds, so will Jehovah of Hosts screen Jerusalem; screening and delivering, sparing and setting free." The prophet uses the plural, "like fluttering birds," with an object - namely, not so much to represent Jehovah Himself, as the tender care and, as it were, maternal love, into which His leonine fierceness would be changed. This is indicated by the fact, that he attaches the feminine ‛âphōth to the common gender tsippŏrı̄m. The word pâsōăch recals to mind the deliverance from Egypt (as in Isa 30:29) in a very significant manner. The sparing of the Israelites by the destroyer passing over their doors, from which the passover derived its name, would be repeated once more. We may see from this, that in and along with Assyria, Jehovah Himself, whose instrument of punishment Assyria was, would take the filed against Jerusalem (Isa 29:2-3); but His attitude towards Jerusalem is suddenly changed into one resembling the action of birds, as they soar round and above their threatened nests. On the inf. abs. kal (gânōn) after the hiphil, see Ewald, 312, b; and on the continuance of the inf. abs. in the finite verb, 350, a. This generally takes place through the future, but here through the preterite, as in Jer 23:14; Gen 26:13, and Sa1 2:26 (if indeed vegâdēl is the third pers. preterite there).
On the ground of this half terrible, half comforting picture of the future, the call to repentance is now addressed to the people of the prophet's own time. "Then turn, O sons of Israel, to Him from whom men have so deeply departed." Strictly speaking, "to Him with regard to whom (אשׁר) ye are deeply fallen away" (he‛ĕmı̄q, as in Hos 9:9, and sârâh, that which is alienated, alienation, as in Isa 1:5); the transition to the third person is like the reverse in Isa 1:29. This call to repentance the prophet strengthens by two powerful motives drawn from the future.
The first is, that idolatry would one day be recognised in all its abomination, and put away. "For in that day they will abhor every one their silver idols and their gold idols, which your hands have made you for a sin," i.e., to commit sin and repent, with the preponderance of the latter idea, as in Hos 8:11 (compare Kg1 13:34). חטא, a second accusative to עשׂוּ, indicating the result. The prospect is the same as that held out in Isa 30:22; Isa 27:9; Isa 17:8; Isa 2:20.
The second motive is, that Israel will not be rescued by men, but by Jehovah alone; so that even He from whom they have now so deeply fallen will prove Himself the only true ground of confidence. "And Asshur falls by a sword not of a man, and a sword not of a man will devour him; and he flees before a sword, and his young men become tributary. And his rock, for fear will it pass away, and his princes be frightened away by the flags: the saying of Jehovah, who has His fire in Zion, and His furnace in Jerusalem." The lxx and Jerome render this falsely φεύξεται οὐκ (לא) ἀπὸ προσώπου μαχαίρας. לו is an ethical dative, and the prophet intentionally writes "before a sword" without any article, to suggest the idea of the unbounded, infinite, awful (cf., Isa 28:2, beyâd; Psalter, vol. i. p. 15). A sword is drawn without any human intervention, and before this Asshur falls, or at least so many of the Assyrians as are unable to save themselves by flight. The power of Asshur is for ever broken; even its young men will henceforth become tributary, or perform feudal service. By "his rock" most commentators understand the rock upon which the fugitive would gladly have taken refuge, but did not dare (Rosenmller, Gesenius, Knobel, etc.); others, again, the military force of Asshur, as its supposed invincible refuge (Saad., etc.); others, the apparently indestructible might of Asshur generally (Vulgate, Rashi, Hitzig). But the presence of "his princes" in the parallel clause makes it most natural to refer "his rock" to the king; and this reference is established with certainty by what Isa 32:2 affirms of the king and princes of Judah. Luther also renders it thus: und jr Fels wird fur furcht wegzihen (and their rock will withdraw for fear). Sennacherib really did hurry back to Assyria after the catastrophe in a most rapid flight. Minnēs are the standards of Asshur, which the commanders of the army fly away from in terror, without attempting to rally those that were scattered. Thus speaks Jehovah, and this is what He decrees who has His 'ūr and tannūr in Jerusalem. We cannot suppose that the allusion here is to the fire and hearth of the sacrifices; for tannūr does not mean a hearth, but a furnace (from nūr, to burn). The reference is to the light of the divine presence, which was outwardly a devouring fire for the enemies of Jerusalem, an unapproachable red-hot furnace (ignis et caminus qui devorat peccatores et ligna, faenum stipulamque consumit: Jerome).