Ecclesiastes

The book’s title is a Greek calque of the Hebrew word קהלת (from קהל — “to assemble”), which means a preacher in a congregation; therefore, in the Greek translation from Hebrew and, correspondingly, in the Christian canon of the vast majority of confessions, the book is called Ecclesiastes or Ekklēsiastes (from Ancient Greek ἐκκλησιαστής — “a speaker in a gathering”).

The Book of Ecclesiastes is in many ways a unique phenomenon within the Bible, noticeably different from all the other books in the author’s mode of thinking. It is hard to find a book in the Old Testament that has had more influence on readers’ minds over the centuries since it was written[4]. Even thinkers far from religion have turned to it as one of the deepest philosophical treatises.
Objections from Jewish theologians of the Talmud to including the Book of Ecclesiastes in the Bible have been preserved (Shabbat, 30b). It was said directly that it contains heretical views (Vayikra Rabbah, 28a).

Ecclesiastes, describing the picture of the eternal cycle of the universe and of man, says that the accumulation of wealth, honors, offices, pleasures—and even righteous labor and the birth of children—everything has already been “under the sun,” and everything is vanity (meaningless, purposeless).