Charles Ellicott Commentary Daniel 5:22

"And thou his son, O Belshazzar, hast not humbled thy heart, though thou knewest all this," — Daniel 5:22 (ASV)

Though you knew.— The whole history of Nebuchadnezzar was known to Belshazzar. He had not, however, learned the moral lesson conveyed by it. He was therefore doubly guilty in the sight of God, because his blasphemy was wilful.