ה֣וּא צַלְמָ֗א רֵאשֵׁהּ֙ דִּֽי־דְהַ֣ב טָ֔ב חֲד֥וֹהִי וּדְרָע֖וֹהִי דִּ֣י כְסַ֑ף מְע֥וֹהִי וְיַרְכָתֵ֖הּ דִּ֥י נְחָֽשׁ׃
As for that image, its head was of fine gold, its breast and its arms of silver, its belly and its thighs of brass,
Read kabbalistic (mystical) interpretation of Daniel 2:32: and classical mystical sources.