Smith's Bible Dictionary (1863)
(prince of fire) occurs only in (Jeremiah 39:3) and Jere 39:13 There appear to have been two persons in the name among the “princes of the king of Babylon” who accompanied Nebuchadnezzar on his last expedition against Jerusalem. One of these is not marked by any additional title; but the other has the honorable distinction of Rab-mag, probably meaning chief of the Magi [see RAB-MAG], and it is to him alone that any particular interest attaches. In sacred Scripture he appears among the persons who, by command of Nebuchadnezzar, released Jeremiah from prison.
Profane history gives us reason to believe that he was a personage of great importance, who not long afterward mounted the Babylonian throne. He is the same as the monarch called Neriglissar or Neriglissor, who murdered Evil-merodach, the son of Nebuchadnezzar and succeeded him upon the throne. C. 556.