In Ezra, chapter one, verse two, about one hundred and sixty years before the appearance of Cyrus, Isaiah had foretold of a ruler named Cyrus who would permit the return of the Jews to their homeland to rebuild Jerusalem and the temple, as in Isaiah forty-four, verses twenty-six through twenty-eight, and chapter forty-five, verses one, and thirteen, respectively.
Those who showed or interpreted to Cyrus the prophecy of Isaiah concerning himself acquainted him that the God, whose prophet Isaiah was, was worshipped by the Jews, not as the God of their particular country, but as the Creator and Lord of heaven and earth. And Cyrus, though he did not entirely forsake the religion of his country, might acknowledge and revere Jehovah, the God of the Hebrews, as the true and great God. For, though the Jews receive the commandment to worship one God and not to admit another into fellowship with him yet, many in the heathen nations, while they worshipped idols, acknowledged a true and supreme God and often worshipped the gods of other countries in common with their own.
All in those parts of the world, all those big dominions which the Assyrians and Babylonians had possessed, the eastern kings were wont, as they are still, to speak magnificently of their dominions. The gift of these Cyrus ascribes to the great God, through the mentioned prophecy of Isaiah concerning him, which must have carried evidence with it, especially to him who was so highly encouraged by it, or through some special illumination which God had vouchsafed to him, as he had to Nebuchadnezzar and Darius, and some other heathen princes.
Cyrus expressly calls the God of heaven by His Israelitish name Jahve and speaks of a commission from this God to build Him a temple at Jerusalem. So, it was manifest that Cyrus consciously entered into the purposes of Jahve and sought, as far as he was concerned, to fulfill them.