Daniel 2:38 (ESV)

38 and into whose hand he has given, wherever they dwell, the children of man, the beasts of the field, and the birds of the heavens, making you rule over them all you are the head of gold.

Daniel shows here once again that Nebuchadnezzar is really a great world ruler at this time. Nebuchadnezzar understands that he and his kingdom are the golden head of the image, and that he shines like the head of pure gold.