וַיָּ֧שֶׂם לָהֶ֛ם שַׂ֥ר הַסָּרִיסִ֖ים שֵׁמ֑וֹת וַיָּ֨שֶׂם לְדָֽנִיֵּ֜אל בֵּ֣לְטְשַׁאצַּ֗ר וְלַֽחֲנַנְיָה֙ שַׁדְרַ֔ךְ וּלְמִֽישָׁאֵ֣ל מֵישַׁ֔ךְ וְלַעֲזַרְיָ֖ה עֲבֵ֥ד נְגֽוֹ׃
Rashi on Daniel
Belteshazzar He named him after the god of Babylon, which was called Bel, as it is said (4: 5): “whose name is Belteshazzar, like the name of my god.” Teshazzar is the Aramaic expression denoting wisdom.