The Hebrews came in contact principally with two great nations of antiquity, the Egyptians and the Persians; at least it is with them mainly, if not solely, that their literature has preserved any traces of connection: and these traces are chiefly to be found in the books of Moses and in the books of Daniel, Ezra and Esther. As the Persian rule of Babylon did not begin till 536 B.C., one would suppose that the records of the earlier reigns of Nebuchadnezzar and Belshazzar would not supply us with any words of Aryan derivation or connection, and this is undoubtedly a difficulty, as it is for many of the words we meet with in these records that such derivation has been suggested, or any such connection supposed.