Then was Daniel brought in before the king - From this it is clear that he lived in Babylon, though in comparative obscurity. It would seem to be not improbable that he was still known to the queen-mother, who, perhaps, kept up an acquaintance with him on account of his former services.
Art thou that Daniel - This is a clear proof that Belshazzar was not acquainted personally with him. See the note at Daniel 5:11.
Which art of the children of the captivity of Judah - Belonging to those of Judah, or those Jews who were made captives, and who reside in Babylon. See the notes at Daniel 1:3. He could not be ignorant that there were Jews in his kingdom, though he was not personally acquainted with Daniel.
Whom the king my father - Margin, as in Daniel 5:2, Daniel 5:1, “grandfather.”
Brought out of Jewry? - Out of Judea. See Daniel 1:1-3.