Albert Barnes Commentary Daniel 5:24

"Then was the part of the hand sent from before him, and this writing was inscribed." — Daniel 5:24 (ASV)

Then the part of the hand was sent from him—that is, the fingers. See Daniel 5:5.

The meaning is that when it was fully perceived that Belshazzar was not inclined to learn that there was a God in heaven; when he refused to profit by the solemn events that had occurred concerning his predecessor; when his own heart was lifted up with pride, and when he had gone even further than his predecessors had done by the sacrilegious use of the vessels of the temple, thus showing special contempt for the God of heaven, then the mysterious handwriting appeared on the wall. It was then an appropriate time for the Most High God, who had been thus despised and insulted, to come forth and rebuke the proud and impious monarch.