Historical: “The Medes came from Persia and easily conquered Babylon in 538 BC. The walls were destroyed twenty years later, after which the city never again became the capital of an independent, strong Mesopotamian power. Two centuries later, after the Greeks, under Alexander the Great, conquered the Persians, Babylon rapidly declined in commercial and cultural importance as Seleucia became the major city in the area. By the time of Christ, only a few astronomers and mathematicians continued to live in the ancient, sparsely populated city. After they left, Babylon remained a deserted tell (mound), which sand and brush gradually covered until it became a hill used only by wild animals and as grazing land for nomadic flocks.” (Isaiah: Prophet Seer Poet, p. 185)
Scriptural: The important phrase in this verse is the Medes’ lack of regard for silver and gold. Not only is this a reversal, but an indication that the wealth of the mighty of the world will not be able to buy them salvation. The forces that will be arrayed against them (literarily the Medes, symbolically the forces of the righteous) will care for the cause of the Savior, not the things valued by mortals.
2 Ne. 23:18
18 Their bows shall also dash the young men to pieces; and they shall have no pity on the fruit of the womb; their eyes shall not spare children.
The entry of the Medes (again symbolic of the armies of the righteous) will conquer the world with no pity. Once again, this is the symbolic reversal, not a depiction of the actions of this righteous army.