Horse's mouth: "Hugo Grotius (1644) is the first who, like Luther, rejects its Solomonic authorship, erroneously supposing, with him, that it is a collection of diverse sayings of the wise, περὶ τῆς εὐδαιμονίας; but on one point he excellently hits the nail on the head: Argumentum ejus rei habeo multa vocabula, quae non alibi quam in Daniele, Esdra et Chaldaeis interpretibus reperias. If the Book of Koheleth were of old Solomonic origin, then there is no history of the Hebrew language." C. Seow, "Linguistic Evidence and the Dating of Qohelet", Journal of Biblical Literature 115 (1996): 643-666. Conclusion: "The language of the book of Qohelet clearly belongs to the postexilic period" (p. (Seow authored the Anchor Bible commentary on Ecclesiastes.) is one of the latest, if nor the latest, of the books of the Old Testament, as indicated above all by the language in which it is written, which, though unique in various ways, has close affinities with post-biblical Hebrew.
The was written much earlier, when the consensus is that it was written later than these other books.
In no way, for example, does it specifically resemble the Hebrew of Malachi, Esther, or of the Chronicler.
Thus some would regard all the edifying passages as interpolations (so Haupt, "Oriental Studies," pp.
This inconsistency, which could probably be paralleled from the works of Oriental pessimists like Omar Khayyam and Abu al-'Ala of Ma'arrah, attracted attention, as has been stated, in early times; but the various attempts that have been made to bring the author into harmony with himself are too subjective to be convincing.
Hebrew writers wouldn't have encountered the Persian language before then.
So the secular history of Ecclesiastes is that it was written during this time, not by King Solomon in the 10th century.
'Ecclesiastes' is the Greek translation of the word Quohelet interpreted officially as a proper name of the writer to whom the text is attributed.