EW:
I apologise for the delay, but I've finally been able to look at Isa.45:7. I've honestly not had the time to devote to it previously. After forming an opinion on the text I hooked out a few commentaries, and it turns out they concur with my opinion, and elaborate on the meaning Cyrus would have taken from it. I'll highlight my opinions, as found.
Starting with John Gill - esteemed hyper-calvinist, and predecessor to Spurgeon's pulpit:
Isa 45:7 - I form the light, and create darkness,.... Natural light, or that light which was produced at the first creation, and of which the sun is the fountain and source; or day which is light, and night which is darkness, the constant revolutions of which were formed, appointed, and are continued by the Lord, Gen.1:3, moral light, or the light of nature, the rational understanding in man; spiritual light, or the light of grace, by which things spiritual and supernatural are known; the light of joy and comfort from Christ, the sun of righteousness; and the light of eternal glory and happiness: this is all from God, of his producing and giving; and so darkness is his creature; that natural darkness which was upon the face of the earth at the beginning; what arises from the absence of the sun, or is occasioned by the eclipses of it, or very black clouds; or any extraordinary darkness, such as was in Egypt; or deprivation of sight, blindness in men; and, in a figurative sense, ignorance and darkness that follow upon sin; judicial blindness, God gives men up and leaves them to; temporal afflictions and distresses, and everlasting punishment, which is blackness of darkness: I make peace, and create evil; peace between God and men is made by Christ, who is God over all; spiritual peace of conscience comes from God, through Christ, by the Spirit; eternal glory and happiness is of God, which saints enter into at death; peace among the saints themselves here, and with the men of the world; peace in churches, and in the world, God is the author of, even of all prosperity of every kind, which this word includes: "evil" is also from him; not the evil of sin; this is not to be found among the creatures God made; this is of men, though suffered by the Lord, and overruled by him for good: but the evil of punishment for sin, God's sore judgments, famine, pestilence, evil beasts, and the sword, or war, which latter may more especially be intended, as it is opposed to peace; this usually is the effect of sin; may be sometimes lawfully engaged in; whether on a good or bad foundation is permitted by God; moreover, all afflictions, adversities, and calamities, come under this name, and are of God; see Job.2:10, I the Lord do all these things; and therefore must be the true God, and the one and only one. Kimchi, from Saadiah Gaon, observes, that this is said against those that assert two gods, the one good, and the other evil; whereas the Lord is the Maker of good and evil, and therefore must be above all; and it is worthy of observation, that the Persian Magi, before Zoroastres (m), held two first causes, the one light, or the good god, the author of all good; and the other darkness, or the evil god, the author of all evil; the one they called Oromazes, the other Arimanius; and, as Dr. Prideaux (n) observes, "these words are directed to Cyrus king of Persia, and must be understood as spoken in reference to the Persian sect of the Magians; who then held light and darkness, or good and evil, to be the supreme Beings, without acknowledging the great God as superior to both;'' and which these words show; for Zoroastres, who reformed them in this first principle of their religion, was after Isaiah's time.
Also Adam Clarke further elaborates:
Isa 45:7 - I form the light, and create darkness - It was the great principle of the Magian religion, which prevailed in Persia in the time of Cyrus, and in which probably he was educated, that there are two supreme, co-eternal, and independent causes always acting in opposition one to the other; one the author of all good, the other of all evil. The good being they called Light; the evil being, Darkness. That when Light had the ascendant, then good and happtness prevailed among men; when Darkness had the superiority, then eviI and misery abounded. An opinion that contradicts the clearest evidence of our reason, which plainly leads us to the acknowledgment of one only Supreme Being, infinitely good as well as powerful. With reference to this absurd opinion, held by the person to whom this prophecy is addressed, God, by his prophet, in the most significant terms, asserts his omnipotence and absolute supremacy: -
?I am Jehovah, and none else;
Forming light, and creating darkness,
Making peace, and creating evil:
I Jehovah am the author of all these things.?
Declaring that those powers whom the Persians held to be the original authors of good and evil to mankind, representing them by light and darkness, as their proper emblems, are no other than creatures of God, the instruments which he employs in his government of the world, ordained or permitted by him in order to execute his wise and just decrees; and that there is no power, either of good or evil, independent of the one supreme God, infinite in power and in goodness.
There were, however, some among the Persians whose sentiments were more moderate as to this matter; who held the evil principle to be in some measure subordinate to the good; and that the former would at length be wholly subdued by the latter. See Hyde, De Relig. Vet. Pers. cap. xxii.That this opinion prevailed among the Persians as early as the time of Cyrus we may, I think, infer not only from this passage of Isaiah, which has a manifest reference to it, but likewise from a passage in Xenophon?s Cyropaedia, where the same doctrine is applied to the human mind. Araspes, a noble young Persian, had fallen in love with the fair captive Panthea, committed to his charge by Cyrus. After all his boasting that he was superior to the assaults of that passion, he yielded so far to it as even to threaten violence if she would not comply with his desires. Awed by the reproof of Cyrus, fearing his displeasure, and having by cool reflection recovered his reason; in his discourse with him on this subject he says: ?O Cyrus, I have certainly two souls; alld this piece of philosophy I have learned from that wicked sophist, Love. For if I had but one soul, it would not be at the same time good and evil, it would not at the same time approve of honorable and base actions; and at once desire to do, and refuse to do, the very same things. But it is plain that I am animated by two souls, and when the good soul prevails, I do what is virtuous; and when the evil one prevails, I attempt what is vicious. But now the good soul prevails, having gotten you for her assistant, and has clearly gained the superiority.? Lib. 6 p. 424.
I make peace, and create evil - Evil is here evidently put for war and its attendant miseries. I will procure peace for the Israelites, and destroy Babylon by war. I form light, and create darkness. Now, as darkness is only the privation of light, so the evil of war is the privation of peace.