Then was King Belshazzar greatly troubled, and his countenance was changed in him, and his lords were astonied. This verse presents signs also of being a repetition. The last clause appears to be the original form of the mysterious clause at the end of the sixth verse according to the Septuagint; the word mishtabsheen, which occurs here, seems to have been read mishtabhareen, from שַׁבְהַר (shab'har), "to be glorious," in the ittaphel; this becomes "to boast one's self," as in the Targum of Proverbs 25:14, also the Peshitta of the same passage; also 2 Corinthians 12:1.
And this is the word used by Paulus Tellensis to translate καυχῶνται. The Septuagint has a verse here that has no equivalent in the Massoretic text, "Then the king called the queen about the sign, and showed her how great it was, and that no one had been able to declare to the king the interpretation of the writing."
This verse avoids the repetition we find in the Massoretic text, and explains the presence of the queen in a much more plausible way than the received text does. In the Massoretic text it is the noise and tumult that pierces the women's apartments, and brings out the queen-mother; though not impossible, this is unlikely.
The action of the king, as given in the Septuagint, is very probable. The wise men are baffled by this mysteriously appearing inscription. What is to be done? Belshazzar calls his mother, the daughter of Nebuchadnezzar, as she at least possibly was, to see if she knows anything in the past that might be a guide in such a matter.
He not only shows her the sign, the inscription, but shows how great it was, by telling of the hand that had come out of the darkness, and had written it. Theodotion and the Peshitta agree with the Massoretic text.
While the repetition is obvious, it is also true that the failure of all the wise men in Babylon to read the writing, as the Massoretic text has it, would increase the trouble of the king, and this trouble would naturally spread to the courtiers.