The head of the statue was pure gold, its chest and arms were silver, its belly and thighs were bronze,
Nebuchadnezzar worshipped images, so God sent him a dream of a great statue to show him what his idols truly were: mere dreams, creatures of fancy that cost treasure and labor but signified nothing. The King had shown kindness to this poor prophet, and now received a prophet's reward that no money could buy.
AI summary
Commenting on Daniel 2:31-45
This image's head was of fine gold,.... The prophet begins with the superior part of this image, and descends to the lower, because of the order and condition of the monarchies it represents: this signifies the Babylonian monarchy, as afterwards explained; called the "head", being the first and chief of the monarchies; and compared to "fine gold", because of the glory, excellency, and duration of...
On ancient coins states are often represented by human figures. The head and higher parts signify the earlier times; the lower, the later times. The metals become successively baser and baser, implying the growing degeneracy from worse to worse. Hesiod, two hundred years before Daniel, had compared the four ages to the four metals in the same order; the idea is sanctioned here by Holy Writ.