My posts on the previous page only dealt with internal evidence that Deutero-Isaiah (ch. 40-55) represents a unit within Isaiah that dates almost two centuries later than the putative author of most of the material prior to ch. 40. The strongest evidence imo of the sixth-century BC date of Deutero-Isaiah is the literary connection with external Persian writings that were circulated at that time. Chapters 40-48 of Deutero-Isaiah closely parallel both the Cyrus Proclamation (the first half of the text in particular, which probably reused earlier anti-Nabonidus propaganda) and ch. 44 of the Yasna, one of the oldest Zoroastrian treatises (from the Gathas, dating to between the eleventh and the seventh centuries BC).
Here is a comparison of Deutero-Isaiah and the Cyrus Proclamation (presented synoptically with the passages from Deutero-Isaiah ordered to match):
Cyrus Proclamation: "He [Nabonidus] continually inflicted evil upon the city of Marduk, daily imposing a yoke upon its inhabitants without relief, ruining them all. Upon hearing their complaints, the Lord of the gods became terribly angry and left them and the other gods living among them left their habitations, angry that he had brought them into Babylon. But Marduk turned back from his fury on account of the fact that all their habitations and sanctuaries were in ruins and the inhabitants of Sumer and Akkad became like corpses, and he abated his anger and had mercy on them. He examined and looked through all the countries, searching everywhere for a righteous king. He took his favoriteby the hand and called out his name: Cyrus, king of Anshan; he pronounced his name as king over the entire world. He made all those of Gutium and all the Manda hordes bow in submission to his feet. And he [Cyrus] always endeavored to treat the blackheaded people according to justice whom Marduk had made him conquer. Marduk, the great lord, a protector of his people, beheld with pleasure his good deeds and his upright mind and thus ordered him to march against his city of Babylon. He ordered him to set out on the road to Babylon, going forth at his side as a companion and friend....All the people of Babylon, all the land of Sumer and Akkad, princes and governors, bowed before him and kissed his feet, rejoicing at his rulership" (lines 8-19).
Deutero-Isaiah: "O daughter of Babylon, I was angry with my people [Jerusalem] and desecrated my inheritance, ... pouring on them my furious anger; I gave them into your hand, and you [the Babylonians] showed them no mercy. Even on the aged you [the Babylonians] laid a very heavy yoke.... Speak tenderly to Jerusalem and cry to her that her warfare is ended, that her iniquity is pardoned, that she has received from Yahweh's hand double for all her sins.... This is what Yahweh says to his anointed, to Cyrus, whose right hand I have grasped to subdue nations before him ... I call you by your name... I am Yahweh, I have called you [Cyrus] in righteousness, I have taken you by the hand and kept you... The wealth of Egypt and the merchandise of Ethiopia and the Sabeans will come over to you and will be yours, they will trudge behind you, coming over to you in chains. They will bow before you and plead with you....Here is my servant whom I uphold, my chosen one in whom I delight; I will put my spirit on him and he will bring justice to the nations.... He will not falter or be discouraged until he establishes justiceon the earth.... [Yahweh] says of Cyrus, he is my friend/shepherd, and he will accomplish all that I wish.... Yahweh's chosen ally will carry out his purpose against Babylon; his arm will be against the Babylonians. I, even I, have spoken; yes, I have called him. I will bring him, and he will succeed in his mission.... I will send him to Babylon and bring down as fugitives all the Babylonians.... This is what Yahweh says to his anointed, to Cyrus ... I will go before you and I will level the mountains and smash the gates of bronze and cut through the bars of iron.... He hands nations over to him and subdues kings before him. He turns them to dust with his sword, to windblown chaff with his bow.... Loss of children and widowhood will come upon you [daughter of Babylon] in full measure, disaster will come upon you and you will not know how to conjure it away and a calamity will fall upon you" (Isaiah 41:2, 42:1, 4, 6, 25, 43:14, 44:28, 45:1-3, 14, 47:5-6, 9-11, 48:14-15).
Here the two texts are closely parallel....just replace "Marduk" with "Yahweh" and "Babylon" in the first portion of the Cyrus Proclamation with "Jerusalem". In both texts, (1) Marduk/Yahweh was angry with Babylon/Jerusalem, (2) Nabonidus/the Babylonians laid a heavy yoke on Babylon/Jerusalem, (3) Marduk/Yahweh turned away from his anger and forgives Babylon/Jerusalem, (4) Marduk/Yahweh chooses Cyrus as his favored king to make things right with Babylon/Jerusalem, (5) Marduk/Yahweh takes Cyrus by the hand, (6) Marduk/Yahweh calls Cyrus by his name, (7) Cyrus is referred to as Marduk/Yahweh's friend or ally, (8) Marduk/Yahweh establishes Cyrus as the king of all nations, (9) Vassal nations are named as subject to Cyrus and bowing before him, (10) Cyrus establishes justice to the peoples, (11) Marduk/Yahweh sends Cyrus to Babylon to accomplish his will against the city, (12) Marduk/Yahweh goes forth at Cyrus' side or before him. The description of the fall of Babylon however diverge between the two -- the Cyrus Proclamation reports a peaceful takeover of the city whereas Deutero-Isaiah predicts a calamatous assault, with the city gates smashed, an obliteration of the people like chaff with sword and bow, and a wholesale loss of the city's population -- either through death or dispersion as escapees.
Also striking is the possible connection between Deutero-Isaiah and the Zoroastrian Yasna. Here is another set of comparisons:
Yasna: "When in the beginning he thought to himself, 'Let the blessed realms be filled with light,' he alone created Justice through his wisdom. Those realms acquired by Good Mind are exalted by you, O Mazda, through the spirit which, O Ahura, is the same evermore. I realized in my mind, O Mazda, that you the first are also the last, that you are the father of Good Mind, and I see with my eyes that you are the true creator of Justice and the Lord to judge the actions of life" (31:7-8).
Deutero-Isaiah: "I form light and create darkness; I make good and create evil. I, Yahweh, do all these things.... Who has done this and carried it through, calling forth the generations from the beginning? I, Yahweh, with the first of them and with the last -- I am he... I am the first and I am the last; apart from me there is no God.... Let salvation spring up, let justice grow with it, I, Yahweh, have created it... I am he; I am the first and I am the last" (Isaiah 41:4, 44:6, 45:6-8, 48:12).
Yasna: "Who was, from the first, the father of Justice? Who determined the courses of the sun and the stars? Who is it by whom the moon waxes and wanes again? ... Who fixed the earth below and the firmament above that it should not fall?Who has set in place the waters and the plants? Who has yoked swiftness to the wind and the clouds? Who is, O Mazda, the creator of Good Thought? This I ask you, tell me truly, Ahura. What craftsman made light and darkness, what craftsman made sleep and waking? Who made morning, afternoon, and evening, to indicate the tasks appointed to those who are perceptive?" (44:3-5).
Deutero-Isaiah: "Let salvation spring up, let justice grow with it, I, Yahweh, have created it... Who created all the starry host, he who brings them out one by one and calls them each by name? ....Who marked out the heavens with the breadth of his hand, or enclosed the dust of the earth in a measure, or weighed the mountains on the scales and the hills in a balance? Who has understood the mind of Yahweh or instructed him as his counselor? Whom did Yahweh consult to enlighten him, and who taught or showed him the path of understanding?.... I, Yahweh, who created all things, who stretched out the heavens alone, who spread out the earth.... My hand laid the foundations of the earth and my right hand spread out the heavens.... Who measured the waters in the hollow of his hand?.... I will put in the wilderness the cedar, the acacia, the myrtle and the olive. I will set in the desert the cypress, the palm, and the pine together.... I will pour water on the thirsty ground and streams on the dry land.... I form light and create darkness; I make good and create evil. I, Yahweh, do all these things" (Isaiah 40:12-14, 26, 41:19, 44:24, 45:7-8, 18, 48:13)
Here "Yahweh" replaces "Ahura Mazda", the one God of Zoroastrianism. In the first passage, Ahura Mazda creates both light and justice in the beginning, who is referred to as the first and the last. Deutero-Isaiah expresses similar thoughts. In the second passage, different parts of the cosmos are mentioned and the rhetorical question is asked to Ahura Mazda, "Who created these things?" The implied answer is, "I am he who did this". Deutero-Isaiah also has a series of similar cosmological questions, this time uttered by Yahweh, with him frequently answering his own question, "I am he". Interestingly, both "Zoroaster" and Deutero-Isaiah have their monotheistic gods create both darkness and light -- the two opposites in Zoroastrian dualism. There are other similarities with the Yasna. In Yasna 12:1, the believer curses the gods (daevas) and professes himself a worshipper of Ahura Mazda. In ch. 32, he contrasts the true believer who "is united with Good Thought and is in friendly partnership with glorious Justice" with those who worship the gods; the gods are "manifestations of Evil Thought" and their worshippers are "manifestations of Falsehood and Dissent" who are led by "Evil Thought and Evil Word" to Falsehoods (v. 3-5). Deutero-Isaiah has a polemic against those who make idols, those "who shape a god and worships it"; such people "know nothing, they understand nothing" and cannot understand (Isaiah 44:9-10, 15, 17-18). It is not quite the same thought since the Yasna knows nothing of Deutero-Isaiah's aniconism and the gods for the Yasna are not nonexistent but manifestations of Evil Thought.
Although the Yasna was probably written earlier than the time of the prophet Isaiah (the traditional date is the seventh century BC, but many current scholars reject this dating), there is no evidence that it had a circulation outside of Persia during the period of Assyrian hegemony (much less to the west in Judea), or that its ideas made an impression elsewhere before the sixth century BC. The mid-sixth century BC date of Deutero-Isaiah however accords well with the Persian influence that spread at the time.
