We should remind ourselves that Isaiah is famous for his predictions concerning the rise and fall of nations. What made him famous is the fact that every prediction came true without a single exception. We also need to keep in mind that his prophetic vision extended from the ancient nations right on down to our modern times. He saw the same thing happening to the wicked in our day that he had seen occurring to the wicked in ancient times. He therefore addresses himself to the wicked and the righteous right down through history. Great political leaders of all ages need to pay attention to Isaiah. Everything he predicts comes true.
The story of the Babylonian empire and its collapse in a single night is rather fantastic. It was Babylon that conquered the Jews in 587 B.C. just 13 years after Lehi and his family left Jerusalem. It was Babylon that destroyed the temple of Solomon, demolished Jerusalem's mighty walls and devastated the whole city. It was the Babylonians who hauled off the survivors to the city of Babylon and might have kept them captive forever if Cyrus had not conquered Babylon in 539 B.C.Notice that the pending fall of Babylon was not whispered to Isaiah by the Spirit, but he was shown an open vision of what would happen nearly 200 years before it would occur.
In verse 2, the Lord tells the leaders who will conquer Babylon to lift up their military banners. The Lord is addressing Cyrus and the hosts of the Medes and Persian whom Cyrus will assemble in the highlands east of the Tigris River. They are to lift up their banners and descend on the nobles of Babylon. It is interesting that in the brass plates Joseph Smith was inspired to write "my banner" suggesting that Cyrus is representing the rod of God's wrath as he goes forth to conquer Babylon.
In verse 3 the Lord speaks of Cyrus and his hosts as the "sanctified ones" who will be blessed with a great victory. Part of this verse has been mutilated. It says God's anger is upon those who rejoice in his highness. The brass plates said God's anger is not against those who rejoice in his highness. Joseph Smith therefore made the necessary correction.