Syriack [Syriac]
From (Daniel 2:4); (Daniel 7:28) the Book of Daniel is written in Aramaic, the ancient language of Syria, and substantially identical with Chaldaic, the language of ancient Babylonia. Upon this fact, together with the occurrence of fifteen Persian, and three Greek words has been based an argument against the historicity of Daniel, and in favour of a date after the conquest of Palestine by Alexander (B.C. 332). It has, however, seemed, with some modern exceptions, to the Hebrew and Christian scholarship of the ages an unanswerable proof rather of the Danielic authorship of the book that, living from boyhood in a land the language of which was Chaldaic, a great part of his writing should be in that tongue. It has often been pointed out that the Chaldaic of Daniel is of high antiquity, as is shown by comparison with that of the Targums. The few words of Persian and Greek in like manner confirm the writer's residence at a court constantly visited by emissaries from those peoples. It is noteworthy that the Aramaic section is precisely that part of Daniel which most concerned the peoples amongst whom he lived, and to whom a prophecy written in Hebrew would have been unintelligible. The language returns to Hebrew in the predictive portions which have to do with the future of Israel.
"The Hebrew of Daniel is closely related to that of Ezekiel." -- Delitzsch.