Daniel 5:18 - Albert Barnes' Notes on the Bible

O thou king, the most high God gave Nebuchadnezzar thy father a kingdom ... - This reference to Nebuchadnezzar is evidently designed to show to Belshazzar the wickedness of his own course, and the reason which he had to apprehend the Divine vengeance, because he had not learned to avoid the sins which brought so great calamities upon his predecessor. As he was acquainted with what had occurred to Nebuchadnezzar; as he had doubtless seen the proclamation which he had made on his recovery from the dreadful malady which God had brought upon him for his pride; and as he had not humbled himself, but had pursued the same course which Nebuchadnezzar did, he had the greater reason to apprehend the judgment of heaven. See Daniel 5:22-23. Daniel here traces all the glory which Nebuchadnezzar had to “the most high God,” reminding the king that whatever honor and majesty he had he was equally indebted for it to the same source, and that he must expect a similar treatment from him.