Why, who and what is Kohelet on Sukkot?

כ אמר רב יהודה בריה דרב שמואל בר שילת משמיה דרב בקשו חכמים לגנוז ספר קהלת מפני שדבריו סותרין זה את זה ומפני מה לא גנזוהו מפני שתחילתו דברי תורה וסופו דברי תורה תחילתו דברי תורה דכתיב (קהלת א, ג) מה יתרון לאדם בכל עמלו שיעמול תחת השמש ואמרי דבי ר' ינאי תחת השמש הוא דאין לו קודם שמש יש לו סופו דברי תורה דכתיב (קהלת יב, יג) סוף דבר הכל נשמע את האלהים ירא ואת מצותיו שמור כי זה כל האדם

Rav Yehudah son of Rav Shmuel bar Shilat said in Rav's name: The Sages wished to hide the Book of Kohelet, because its words are contradictory. And why did they not hide it? Because it begins with words of Torah and it ends with words of Torah. It begins with words of Torah as it is written, What profit has man of all his labor that he labors under the sun (1:3)? And the School of R. Yannai commented: Under the sun he has none, but he has it [profit] before the sun. It ends with words of Torah, as it is written, Let us hear the conclusion of the matter, fear God, and keep his mitzvot: for this is the whole of man (12:13).

מסכת סופרים י"ד:ג

ברות ובשיר השירים באיכה ובמגלת אסתר צריך ולומר על מקרא מגילה ואע"פ שכתובה בכתובים:

Tractate Sofrim 14:3

On Rut, Shir Hashirim, Eicha and Esther we bless "regarding the reading of the scroll", even though they are in Ketuvim.

>>> The simple reason seems to have been a desire to read all five scrolls of the Bible in public. Esther was read on Purim; Eikhah was read on Tisha B'av ; Shir Hashirim which transpires in the spring was read on Pesah , Hag He'aviv , the spring festival; and Ruth, which transpires during the wheat harvest, was read on Shavuot . This left one scroll - Kohelet - and one pilgrim festival - Sukkot - which were eventually matched up. (Rabbi David Golinkin) The blessing is said only if we are reading them on parchment.

אמר רבה דאמר קרא (ויקרא כג, מג) למען ידעו דורותיכם כי בסוכות הושבתי את בני ישראל עד עשרים אמה אדם יודע שהוא דר בסוכה למעלה מעשרים אמה אין אדם יודע שדר בסוכה משום דלא שלטא בה עינא...ורבא אמר מהכא (ויקרא כג, מב) בסוכות תשבו שבעת ימים אמרה תורה כל שבעת הימים צא מדירת קבע ושב בדירת עראי עד עשרים אמה אדם עושה דירתו דירת עראי למעלה מעשרים אמה אין אדם עושה דירתו דירת עראי אלא דירת קבע

Rabbah said: As it says in the Torah: (Leviticus 23:43) "In order that your generations will know that I settled the children of Israel in sukkot." Until twenty amot, a person knows that he is dwelling in a sukkah [because his eye will catch sight of the roofing and remind him of the sukkah and its associated mitzvot]. Above twenty amot, a person does not know that he is dwelling in a sukkah, because it is not in his field of vision... Rava replied: From the following verse, "You shall dwell in sukkot for seven days" (Leviticus 23:42) the Torah declared: For seven days leave your permanent dwelling place and dwell in a temporary dwelling place. Up to twenty cubits [high] one makes his home a temporary one; higher than twenty cubits, one does not make his home temporary, but permanent.

>>>>>Sukkot is the bridge between permanence and impermanence. 20 amot/30 feet is the limit of permanence and of awareness of the impermanence.

Hevel - impermanence - is also the name of Abel. In that sense, Abel only existed for a moment.

"The book of Ecclesiastes is a philosophical account of the attempt to find happiness by a man who has everything. ... Twelve chapters long, it is one of literature’s earliest encounters between faith and reason: The author struggles to believe that life is meaningful despite his experience of the world. The book’s inclusion in the Hebrew Bible is therefore remarkable, testifying to Judaism’s interest not only in divine revelation, but also in man’s exploration of the meaning of life and mortality. The search for meaning is an eternal one, but the use of Solomon’s voice carries special importance for the modern reader. ... As opposed to the quest of Job, Solomon’s search for wisdom did not arise from a desire to make sense of either personal misfortune or national catastrophe... Rather, Kohelet sets out on his inquiry from the perspective of a life replete with fortune and opportunity. He takes as his starting point not revelation, but man’s personal need for meaning." (Ethan Dor-Shav, Azure no. 18, Ecclesiastes: Fleeting and Timeless)

(ב) הֲבֵ֤ל הֲבָלִים֙ אָמַ֣ר קֹהֶ֔לֶת הֲבֵ֥ל הֲבָלִ֖ים הַכֹּ֥ל הָֽבֶל׃ (ג) מַה־יִּתְר֖וֹן לָֽאָדָ֑ם בְּכָל־עֲמָל֔וֹ שֶֽׁיַּעֲמֹ֖ל תַּ֥חַת הַשָּֽׁמֶשׁ׃ (ד) דּ֤וֹר הֹלֵךְ֙ וְד֣וֹר בָּ֔א וְהָאָ֖רֶץ לְעוֹלָ֥ם עֹמָֽדֶת׃

(2) Transience of transiences, says Koheleth; Transience of transiences, all is transience. (3) What profit has man of all his labor that he labours under the sun? (4) One generation passes away, and another generation comes; and the earth stands for ever.

(א) וְהָ֣אָדָ֔ם יָדַ֖ע אֶת־חַוָּ֣ה אִשְׁתּ֑וֹ וַתַּ֙הַר֙ וַתֵּ֣לֶד אֶת־קַ֔יִן וַתֹּ֕אמֶר קָנִ֥יתִי אִ֖ישׁ אֶת־יְהוָֽה׃ (ב) וַתֹּ֣סֶף לָלֶ֔דֶת אֶת־אָחִ֖יו אֶת־הָ֑בֶל וַֽיְהִי־הֶ֙בֶל֙ רֹ֣עֵה צֹ֔אן וְקַ֕יִן הָיָ֖ה עֹבֵ֥ד אֲדָמָֽה׃

(1) And the man knew Eve his wife; and she conceived and bore Cain, and said: ‘I have agotten a man with the help of the LORD.’ (2) And again she bore his brother Abel. And Abel was a keeper of sheep, but Cain was a tiller of the ground.

Franz Rozensweig Star of Redemption, transl. William Halo, 1985, p. 3

"All cognition of the All originates in death, in the fear of death."

(א) אָמַ֤רְתִּֽי אֲנִי֙ בְּלִבִּ֔י לְכָה־נָּ֛א אֲנַסְּכָ֛ה בְשִׂמְחָ֖ה וּרְאֵ֣ה בְט֑וֹב וְהִנֵּ֥ה גַם־ה֖וּא הָֽבֶל׃ (ב) לִשְׂח֖וֹק אָמַ֣רְתִּי מְהוֹלָ֑ל וּלְשִׂמְחָ֖ה מַה־זֹּ֥ה עֹשָֽׂה׃ (ג) תַּ֣רְתִּי בְלִבִּ֔י לִמְשׁ֥וֹךְ בַּיַּ֖יִן אֶת־בְּשָׂרִ֑י וְלִבִּ֞י נֹהֵ֤ג בַּֽחָכְמָה֙ וְלֶאֱחֹ֣ז בְּסִכְל֔וּת עַ֣ד אֲשֶׁר־אֶרְאֶ֗ה אֵי־זֶ֨ה ט֜וֹב לִבְנֵ֤י הָאָדָם֙ אֲשֶׁ֤ר יַעֲשׂוּ֙ תַּ֣חַת הַשָּׁמַ֔יִם מִסְפַּ֖ר יְמֵ֥י חַיֵּיהֶֽם׃ (ד) הִגְדַּ֖לְתִּי מַעֲשָׂ֑י בָּנִ֤יתִי לִי֙ בָּתִּ֔ים נָטַ֥עְתִּי לִ֖י כְּרָמִֽים׃ (ה) עָשִׂ֣יתִי לִ֔י גַּנּ֖וֹת וּפַרְדֵּסִ֑ים וְנָטַ֥עְתִּי בָהֶ֖ם עֵ֥ץ כָּל־פֶּֽרִי׃ (ו) עָשִׂ֥יתִי לִ֖י בְּרֵכ֣וֹת מָ֑יִם לְהַשְׁק֣וֹת מֵהֶ֔ם יַ֖עַר צוֹמֵ֥חַ עֵצִֽים׃ (ז) קָנִ֙יתִי֙ עֲבָדִ֣ים וּשְׁפָח֔וֹת וּבְנֵי־בַ֖יִת הָ֣יָה לִ֑י גַּ֣ם מִקְנֶה֩ בָקָ֨ר וָצֹ֤אן הַרְבֵּה֙ הָ֣יָה לִ֔י מִכֹּ֛ל שֶֽׁהָי֥וּ לְפָנַ֖י בִּירוּשָׁלִָֽם׃ (ח) כָּנַ֤סְתִּי לִי֙ גַּם־כֶּ֣סֶף וְזָהָ֔ב וּסְגֻלַּ֥ת מְלָכִ֖ים וְהַמְּדִינ֑וֹת עָשִׂ֨יתִי לִ֜י שָׁרִ֣ים וְשָׁר֗וֹת וְתַעֲנוּגֹ֛ת בְּנֵ֥י הָאָדָ֖ם שִׁדָּ֥ה וְשִׁדּֽוֹת׃ (ט) וְגָדַ֣לְתִּי וְהוֹסַ֔פְתִּי מִכֹּ֛ל שֶׁהָיָ֥ה לְפָנַ֖י בִּירוּשָׁלִָ֑ם אַ֥ף חָכְמָתִ֖י עָ֥מְדָה לִּֽי׃ (י) וְכֹל֙ אֲשֶׁ֣ר שָֽׁאֲל֣וּ עֵינַ֔י לֹ֥א אָצַ֖לְתִּי מֵהֶ֑ם לֹֽא־מָנַ֨עְתִּי אֶת־לִבִּ֜י מִכָּל־שִׂמְחָ֗ה כִּֽי־לִבִּ֤י שָׂמֵ֙חַ֙ מִכָּל־עֲמָלִ֔י וְזֶֽה־הָיָ֥ה חֶלְקִ֖י מִכָּל־עֲמָלִֽי׃ (יא) וּפָנִ֣יתִֽי אֲנִ֗י בְּכָל־מַעֲשַׂי֙ שֶֽׁעָשׂ֣וּ יָדַ֔י וּבֶֽעָמָ֖ל שֶׁעָמַ֣לְתִּי לַעֲשׂ֑וֹת וְהִנֵּ֨ה הַכֹּ֥ל הֶ֙בֶל֙ וּרְע֣וּת ר֔וּחַ וְאֵ֥ין יִתְר֖וֹן תַּ֥חַת הַשָּֽׁמֶשׁ׃ (יב) וּפָנִ֤יתִֽי אֲנִי֙ לִרְא֣וֹת חָכְמָ֔ה וְהוֹלֵל֖וֹת וְסִכְל֑וּת כִּ֣י ׀ מֶ֣ה הָאָדָ֗ם שֶׁיָּבוֹא֙ אַחֲרֵ֣י הַמֶּ֔לֶךְ אֵ֥ת אֲשֶׁר־כְּבָ֖ר עָשֽׂוּהוּ׃ (יג) וְרָאִ֣יתִי אָ֔נִי שֶׁיֵּ֥שׁ יִתְר֛וֹן לַֽחָכְמָ֖ה מִן־הַסִּכְל֑וּת כִּֽיתְר֥וֹן הָא֖וֹר מִן־הַחֹֽשֶׁךְ׃ (יד) הֶֽחָכָם֙ עֵינָ֣יו בְּרֹאשׁ֔וֹ וְהַכְּסִ֖יל בַּחֹ֣שֶׁךְ הוֹלֵ֑ךְ וְיָדַ֣עְתִּי גַם־אָ֔נִי שֶׁמִּקְרֶ֥ה אֶחָ֖ד יִקְרֶ֥ה אֶת־כֻּלָּֽם׃ (טו) וְאָמַ֨רְתִּֽי אֲנִ֜י בְּלִבִּ֗י כְּמִקְרֵ֤ה הַכְּסִיל֙ גַּם־אֲנִ֣י יִקְרֵ֔נִי וְלָ֧מָּה חָכַ֛מְתִּי אֲנִ֖י אָ֣ז יוֹתֵ֑ר וְדִבַּ֣רְתִּי בְלִבִּ֔י שֶׁגַּם־זֶ֖ה הָֽבֶל׃ (טז) כִּי֩ אֵ֨ין זִכְר֧וֹן לֶחָכָ֛ם עִֽם־הַכְּסִ֖יל לְעוֹלָ֑ם בְּשֶׁכְּבָ֞ר הַיָּמִ֤ים הַבָּאִים֙ הַכֹּ֣ל נִשְׁכָּ֔ח וְאֵ֛יךְ יָמ֥וּת הֶחָכָ֖ם עִֽם־הַכְּסִֽיל׃ (יז) וְשָׂנֵ֙אתִי֙ אֶת־הַ֣חַיִּ֔ים כִּ֣י רַ֤ע עָלַי֙ הַֽמַּעֲשֶׂ֔ה שֶׁנַּעֲשָׂ֖ה תַּ֣חַת הַשָּׁ֑מֶשׁ כִּֽי־הַכֹּ֥ל הֶ֖בֶל וּרְע֥וּת רֽוּחַ׃ (יח) וְשָׂנֵ֤אתִֽי אֲנִי֙ אֶת־כָּל־עֲמָלִ֔י שֶׁאֲנִ֥י עָמֵ֖ל תַּ֣חַת הַשָּׁ֑מֶשׁ שֶׁ֣אַנִּיחֶ֔נּוּ לָאָדָ֖ם שֶׁיִּהְיֶ֥ה אַחֲרָֽי׃ (יט) וּמִ֣י יוֹדֵ֗עַ הֶֽחָכָ֤ם יִהְיֶה֙ א֣וֹ סָכָ֔ל וְיִשְׁלַט֙ בְּכָל־עֲמָלִ֔י שֶֽׁעָמַ֥לְתִּי וְשֶׁחָכַ֖מְתִּי תַּ֣חַת הַשָּׁ֑מֶשׁ גַּם־זֶ֖ה הָֽבֶל׃ (כ) וְסַבּ֥וֹתִֽי אֲנִ֖י לְיַאֵ֣שׁ אֶת־לִבִּ֑י עַ֚ל כָּל־הֶ֣עָמָ֔ל שֶׁעָמַ֖לְתִּי תַּ֥חַת הַשָּֽׁמֶשׁ׃ (כא) כִּי־יֵ֣שׁ אָדָ֗ם שֶׁעֲמָל֛וֹ בְּחָכְמָ֥ה וּבְדַ֖עַת וּבְכִשְׁר֑וֹן וּלְאָדָ֞ם שֶׁלֹּ֤א עָֽמַל־בּוֹ֙ יִתְּנֶ֣נּוּ חֶלְק֔וֹ גַּם־זֶ֥ה הֶ֖בֶל וְרָעָ֥ה רַבָּֽה׃ (כב) כִּ֠י מֶֽה־הֹוֶ֤ה לָֽאָדָם֙ בְּכָל־עֲמָל֔וֹ וּבְרַעְי֖וֹן לִבּ֑וֹ שֶׁה֥וּא עָמֵ֖ל תַּ֥חַת הַשָּֽׁמֶשׁ׃ (כג) כִּ֧י כָל־יָמָ֣יו מַכְאֹבִ֗ים וָכַ֙עַס֙ עִנְיָנ֔וֹ גַּם־בַּלַּ֖יְלָה לֹא־שָׁכַ֣ב לִבּ֑ו גַּם־זֶ֖ה הֶ֥בֶל הֽוּא׃

(1) I said in my heart: ‘Come now, I will try thee with mirth, and enjoy pleasure’; and, behold, this also was vanity. (2) I said of laughter: ‘It is mad’; and of mirth: ‘What doth it accomplish?’ (3) I searched in my heart how to pamper my flesh with wine, and, my heart conducting itself with wisdom, how yet to lay hold on folly, till I might see which it was best for the sons of men that they should do under the heaven the few days of their life. (4) I made me great works; I builded me houses; I planted me vineyards; (5) I made me gardens and parks, and I planted trees in them of all kinds of fruit; (6) I made me pools of water, to water therefrom the wood springing up with trees; (7) I acquired men-servants and maid-servants, and had servants born in my house; also I had great possessions of herds and flocks, above all that were before me in Jerusalem; (8) I gathered me also silver and gold, and treasure such as kings and the provinces have as their own; I got me men-singers and women-singers, and the delights of the sons of men, women very many. (9) So I was great, and increased more than all that were before me in Jerusalem; also my wisdom stood me in stead. (10) And whatsoever mine eyes desired I kept not from them; I withheld not my heart from any joy, for my heart had joy of all my labour; and this was my portion from all my labour. (11) Then I looked on all the works that my hands had wrought, and on the labour that I had laboured to do; and, behold, all was transience and a striving after wind, and there was no profit under the sun. (12) And I turned myself to behold wisdom, and madness and folly; for what can the man do that cometh after the king? even that which hath been already done. (13) Then I saw that wisdom excelleth folly, as far as light excelleth darkness. (14) The wise man, his eyes are in his head; But the fool walketh in darkness. And I also perceived that one event happeneth to them all. (15) Then said I in my heart: ‘As it happeneth to the fool, so will it happen even to me; and why was I then more wise?’ Then I said in my heart, that this also is transience. (16) For of the wise man, even as of the fool, there is no remembrance for ever; seeing that in the days to come all will long ago have been forgotten. And how must the wise man die even as the fool! (17) So I hated life; because the work that is wrought under the sun was grievous unto me; for all is transience and a striving after wind. (18) And I hated all my labour wherein I laboured under the sun, seeing that I must leave it unto the man that shall be after me. (19) And who knoweth whether he will be a wise man or a fool? yet will he have rule over all my labour wherein I have laboured, and wherein I have shown myself wise under the sun. This also is transience. (20) Therefore I turned about to cause my heart to despair concerning all the labour wherein I had laboured under the sun. (21) For there is a man whose labour is with wisdom, and with knowledge, and with skill; yet to a man that hath not laboured therein shall he leave it for his portion. This also is vanity and a great evil. (22) For what hath a man of all his labour, and of the striving of his heart, wherein he laboureth under the sun? (23) For all his days are pains, and his occupation vexation; yea, even in the night his heart taketh not rest. This also is transience.

>>> on the first chapters - Kohelet is bitter about transience: pleasure, riches, accomplishments and physical existence - all transient. Same with fighting for goodness:

(א) וְשַׁ֣בְתִּֽי אֲנִ֗י וָאֶרְאֶה֙ אֶת־כָּל־הָ֣עֲשֻׁקִ֔ים אֲשֶׁ֥ר נַעֲשִׂ֖ים תַּ֣חַת הַשָּׁ֑מֶשׁ וְהִנֵּ֣ה ׀ דִּמְעַ֣ת הָעֲשֻׁקִ֗ים וְאֵ֤ין לָהֶם֙ מְנַחֵ֔ם וּמִיַּ֤ד עֹֽשְׁקֵיהֶם֙ כֹּ֔חַ וְאֵ֥ין לָהֶ֖ם מְנַחֵֽם׃ (ב) וְשַׁבֵּ֧חַ אֲנִ֛י אֶת־הַמֵּתִ֖ים שֶׁכְּבָ֣ר מֵ֑תוּ מִן־הַ֣חַיִּ֔ים אֲשֶׁ֛ר הֵ֥מָּה חַיִּ֖ים עֲדֶֽנָה׃ (ג) וְטוֹב֙ מִשְּׁנֵיהֶ֔ם אֵ֥ת אֲשֶׁר־עֲדֶ֖ן לֹ֣א הָיָ֑ה אֲשֶׁ֤ר לֹֽא־רָאָה֙ אֶת־הַמַּעֲשֶׂ֣ה הָרָ֔ע אֲשֶׁ֥ר נַעֲשָׂ֖ה תַּ֥חַת הַשָּֽׁמֶשׁ׃ (ד) וְרָאִ֨יתִֽי אֲנִ֜י אֶת־כָּל־עָמָ֗ל וְאֵת֙ כָּל־כִּשְׁר֣וֹן הַֽמַּעֲשֶׂ֔ה כִּ֛י הִ֥יא קִנְאַת־אִ֖ישׁ מֵרֵעֵ֑הוּ גַּם־זֶ֥ה הֶ֖בֶל וּרְע֥וּת רֽוּחַ׃
(1) But I returned and considered all the oppressions that are done under the sun; and behold the tears of such as were oppressed, and they had no comforter; and on the side of their oppressors there was power, but they had no comforter. (2) Wherefore I praised the dead that are already dead more than the living that are yet alive; (3) but better than they both is he that hath not yet been, who hath not seen the evil work that is done under the sun. (4) Again, I considered all labour and all excelling in work, that it is a man’s rivalry with his neighbour. This also is vanity and a striving after wind.

The next source begins a clarification that Kohelet needs: a short but good life is better than a long bad one. This clarification is acceptance.

(ג) אִם־יוֹלִ֣יד אִ֣ישׁ מֵאָ֡ה וְשָׁנִים֩ רַבּ֨וֹת יִֽחְיֶ֜ה וְרַ֣ב ׀ שֶׁיִּהְי֣וּ יְמֵֽי־שָׁנָ֗יו וְנַפְשׁוֹ֙ לֹא־תִשְׂבַּ֣ע מִן־הַטּוֹבָ֔ה וְגַם־קְבוּרָ֖ה לֹא־הָ֣יְתָה לּ֑וֹ אָמַ֕רְתִּי ט֥וֹב מִמֶּ֖נּוּ הַנָּֽפֶל׃ (ד) כִּֽי־בַהֶ֥בֶל בָּ֖א וּבַחֹ֣שֶׁךְ יֵלֵ֑ךְ וּבַחֹ֖שֶׁךְ שְׁמ֥וֹ יְכֻסֶּֽה׃ (ה) גַּם־שֶׁ֥מֶשׁ לֹא־רָאָ֖ה וְלֹ֣א יָדָ֑ע נַ֥חַת לָזֶ֖ה מִזֶּֽה׃ (ו) וְאִלּ֣וּ חָיָ֗ה אֶ֤לֶף שָׁנִים֙ פַּעֲמַ֔יִם וְטוֹבָ֖ה לֹ֣א רָאָ֑ה הֲלֹ֛א אֶל־מָק֥וֹם אֶחָ֖ד הַכֹּ֥ל הוֹלֵֽךְ׃

(3) If a man beget a hundred children, and live many years, so that the days of his years are many, but his soul have not enough of good, and moreover he have no burial; I say, that an untimely birth is better than he; (4) for it cometh in vanity, and departeth in darkness, and the name thereof is covered with darkness; (5) moreover it hath not seen the sun nor known it; this hath gratification rather than the other; (6) yea, though he live a thousand years twice told, and enjoy no good; do not all go to one place?

Acceptance leads, then, to happiness on your lot.

(טו) וְשִׁבַּ֤חְתִּֽי אֲנִי֙ אֶת־הַשִּׂמְחָ֔ה אֲשֶׁ֨ר אֵֽין־ט֤וֹב לָֽאָדָם֙ תַּ֣חַת הַשֶּׁ֔מֶשׁ כִּ֛י אִם־לֶאֱכ֥וֹל וְלִשְׁתּ֖וֹת וְלִשְׂמ֑וֹחַ וְה֞וּא יִלְוֶ֣נּוּ בַעֲמָל֗וֹ יְמֵ֥י חַיָּ֛יו אֲשֶׁר־נָֽתַן־ל֥וֹ הָאֱלֹהִ֖ים תַּ֥חַת הַשָּֽׁמֶשׁ׃

(15) So I commended mirth, that a man hath no better thing under the sun, than to eat, and to drink, and to be merry, and that this should accompany him in his labour all the days of his life which God hath given him under the sun.

And that leads to transience as inspiration - urgency to live and to experience joy. Joy becomes an independent value.

(ה) כִּ֧י הַֽחַיִּ֛ים יוֹדְעִ֖ים שֶׁיָּמֻ֑תוּ וְהַמֵּתִ֞ים אֵינָ֧ם יוֹדְעִ֣ים מְא֗וּמָה וְאֵֽין־ע֤וֹד לָהֶם֙ שָׂכָ֔ר כִּ֥י נִשְׁכַּ֖ח זִכְרָֽם׃ (ו) גַּ֣ם אַהֲבָתָ֧ם גַּם־שִׂנְאָתָ֛ם גַּם־קִנְאָתָ֖ם כְּבָ֣ר אָבָ֑דָה וְחֵ֨לֶק אֵין־לָהֶ֥ם עוֹד֙ לְעוֹלָ֔ם בְּכֹ֥ל אֲשֶֽׁר־נַעֲשָׂ֖ה תַּ֥חַת הַשָּֽׁמֶשׁ׃ (ז) לֵ֣ךְ אֱכֹ֤ל בְּשִׂמְחָה֙ לַחְמֶ֔ךָ וּֽשֲׁתֵ֥ה בְלֶב־ט֖וֹב יֵינֶ֑ךָ כִּ֣י כְבָ֔ר רָצָ֥ה הָאֱלֹהִ֖ים אֶֽת־מַעֲשֶֽׂיךָ׃ (ח) בְּכָל־עֵ֕ת יִהְי֥וּ בְגָדֶ֖יךָ לְבָנִ֑ים וְשֶׁ֖מֶן עַל־רֹאשְׁךָ֥ אַל־יֶחְסָֽר׃ (ט) רְאֵ֨ה חַיִּ֜ים עִם־אִשָּׁ֣ה אֲשֶׁר־אָהַ֗בְתָּ כָּל־יְמֵי֙ חַיֵּ֣י הֶבְלֶ֔ךָ אֲשֶׁ֤ר נָֽתַן־לְךָ֙ תַּ֣חַת הַשֶּׁ֔מֶשׁ כֹּ֖ל יְמֵ֣י הֶבְלֶ֑ךָ כִּ֣י ה֤וּא חֶלְקְךָ֙ בַּֽחַיִּ֔ים וּבַעֲמָ֣לְךָ֔ אֲשֶׁר־אַתָּ֥ה עָמֵ֖ל תַּ֥חַת הַשָּֽׁמֶשׁ׃ (י) כֹּ֠ל אֲשֶׁ֨ר תִּמְצָ֧א יָֽדְךָ֛ לַעֲשׂ֥וֹת בְּכֹחֲךָ֖ עֲשֵׂ֑ה כִּי֩ אֵ֨ין מַעֲשֶׂ֤ה וְחֶשְׁבּוֹן֙ וְדַ֣עַת וְחָכְמָ֔ה בִּשְׁא֕וֹל אֲשֶׁ֥ר אַתָּ֖ה הֹלֵ֥ךְ שָֽׁמָּה׃ (ס) (יא) שַׁ֜בְתִּי וְרָאֹ֣ה תַֽחַת־הַשֶּׁ֗מֶשׁ כִּ֣י לֹא֩ לַקַּלִּ֨ים הַמֵּר֜וֹץ וְלֹ֧א לַגִּבּוֹרִ֣ים הַמִּלְחָמָ֗ה וְ֠גַם לֹ֣א לַחֲכָמִ֥ים לֶ֙חֶם֙ וְגַ֨ם לֹ֤א לַנְּבֹנִים֙ עֹ֔שֶׁר וְגַ֛ם לֹ֥א לַיֹּדְעִ֖ים חֵ֑ן כִּי־עֵ֥ת וָפֶ֖גַע יִקְרֶ֥ה אֶת־כֻּלָּֽם׃ (יב) כִּ֡י גַּם֩ לֹֽא־יֵדַ֨ע הָאָדָ֜ם אֶת־עִתּ֗וֹ כַּדָּגִים֙ שֶׁנֶּֽאֱחָזִים֙ בִּמְצוֹדָ֣ה רָעָ֔ה וְכַ֨צִּפֳּרִ֔ים הָאֲחֻז֖וֹת בַּפָּ֑ח כָּהֵ֗ם יֽוּקָשִׁים֙ בְּנֵ֣י הָֽאָדָ֔ם לְעֵ֣ת רָעָ֔ה כְּשֶׁתִּפּ֥וֹל עֲלֵיהֶ֖ם פִּתְאֹֽם׃

(5) For the living know that they shall die; but the dead know not any thing, neither have they any more a reward; for the memory of them is forgotten. (6) As well their love, as their hatred and their envy, is long ago perished; neither have they any more a portion for ever in any thing that is done under the sun. (7) Go thy way, eat thy bread with joy, And drink thy wine with a merry heart; For God hath already accepted thy works. (8) Let thy garments be always white; And let thy head lack no oil. (9) Enjoy life with the wife whom thou lovest all the days of the life of thy vanity, which He hath given thee under the sun, all the days of thy vanity; for that is thy portion in life, and in thy labour wherein thou labourest under the sun. (10) Whatsoever thy hand attaineth to do by thy strength, that do; for there is no work, nor device, nor knowledge, nor wisdom, in the grave, whither thou goest. (11) I returned, and saw under the sun, that the race is not to the swift, nor the battle to the strong, neither yet bread to the wise, nor yet riches to men of understanding, nor yet favour to men of skill; but time and chance happeneth to them all. (12) For man also knoweth not his time; as the fishes that are taken in an evil net, and as the birds that are caught in the snare, even so are the sons of men snared in an evil time, when it falleth suddenly upon them.

But there is wisdom...
(יג) וְרָאִ֣יתִי אָ֔נִי שֶׁיֵּ֥שׁ יִתְר֛וֹן לַֽחָכְמָ֖ה מִן־הַסִּכְל֑וּת כִּֽיתְר֥וֹן הָא֖וֹר מִן־הַחֹֽשֶׁךְ׃
(13) Then I saw that wisdom excelleth folly, as far as light excelleth darkness.
(יב) כִּ֛י בְּצֵ֥ל הַֽחָכְמָ֖ה בְּצֵ֣ל הַכָּ֑סֶף וְיִתְר֣וֹן דַּ֔עַת הַֽחָכְמָ֖ה תְּחַיֶּ֥ה בְעָלֶֽיהָ׃
(12) For wisdom is a defence, even as money is a defence; but the excellency of knowledge is, that wisdom preserveth the life of him that hath it.
(יט) הַֽחָכְמָ֖ה תָּעֹ֣ז לֶחָכָ֑ם מֵֽעֲשָׂרָה֙ שַׁלִּיטִ֔ים אֲשֶׁ֥ר הָי֖וּ בָּעִֽיר׃
(19) Wisdom is a stronghold to the wise man more than ten rulers that are in a city.
(א) מִ֚י כְּהֶ֣חָכָ֔ם וּמִ֥י יוֹדֵ֖עַ פֵּ֣שֶׁר דָּבָ֑ר חָכְמַ֤ת אָדָם֙ תָּאִ֣יר פָּנָ֔יו וְעֹ֥ז פָּנָ֖יו יְשֻׁנֶּֽא׃ (ב) אֲנִי֙ פִּי־מֶ֣לֶךְ שְׁמ֔וֹר וְעַ֕ל דִּבְרַ֖ת שְׁבוּעַ֥ת אֱלֹהִֽים׃ (ג) אַל־תִּבָּהֵ֤ל מִפָּנָיו֙ תֵּלֵ֔ךְ אַֽל־תַּעֲמֹ֖ד בְּדָבָ֣ר רָ֑ע כִּ֛י כָּל־אֲשֶׁ֥ר יַחְפֹּ֖ץ יַעֲשֶֽׂה׃ (ד) בַּאֲשֶׁ֥ר דְּבַר־מֶ֖לֶךְ שִׁלְט֑וֹן וּמִ֥י יֹֽאמַר־ל֖וֹ מַֽה־תַּעֲשֶֽׂה׃ (ה) שׁוֹמֵ֣ר מִצְוָ֔ה לֹ֥א יֵדַ֖ע דָּבָ֣ר רָ֑ע וְעֵ֣ת וּמִשְׁפָּ֔ט יֵדַ֖ע לֵ֥ב חָכָֽם׃
(1) Who is as the wise man? and who knoweth the interpretation of a thing? A man’s wisdom maketh his face to shine, And the boldness of his face is changed. (2) I [counsel thee]: keep the king’s command, and that in regard of the oath of God. (3) Be not hasty to go out of his presence; stand not in an evil thing; for he doeth whatsoever pleaseth him. (4) Forasmuch as the king’s word hath power; and who may say unto him: ‘What doest thou?’ (5) Whoso keepeth the commandment shall know no evil thing; And a wise man’s heart discerneth time and judgment.

What else is fleeting and eternal? The vision of the Burning Bush. One of the works of Kabbalah says that Moshe is actually a reincarnation of Hevel (hold on to your kippas, humor me for a moment, it might actually make sense in the long view of the subject of Kohelet) - Hevel is validated, in this view. He is the only one that began looking after the other, as expressed in his taking care of sheep. Remember the connection between Moshe and sheep?

שער הגלגולים ל"ד:א

והנה משה תחלה היה הבל בן אדה"ר, ואח"כ נתגלגל בשת, ואח"כ בנח, ואח"כ בשם בן נח. וז"ס ואתה אמרת ידעתיך בשם, רמז גלגולו בשם. וגם מצאת חן בעיני, רמז גלגולו בנת אביו. כי נח הם אותיות חן, בסוד ונח מצא חן.

Gate of Reincarnations, Chapter 34, Section 1 - by Rabbi Yitzchak Luria as recorded by Rabbi Chaim Vital; translation by Yitzchok bar Chaim

At first, Moses was Abel, who was the son of Adam. Later, he reincarnated into Seth, then Noah, and after that, into Shem, Noah's son. This is the secret of, "You have said, ‘I shall know you by shem [literally meaning 'name']’" (Ex. 33:12) - an allusion to the reincarnation into Shem. "And you found favor ChN/cheit-nun [favor] in My eyes" hints at the reincarnation into Noah, the father, since Noah also contains the letters ChN/cheit-nun. In the secret of, "Noah found favor CN/cheit-nun [favor](Gen. 6:8)

Wisdom, the greatest accomplishment in Jewish tradition, is also hevel - transient. But it stays longer than other things. Think about Shlomo Hamelech - riches, power, wives, temple - nothing really survived. But his three books - Shir Hashirim/Songs, Mishlei/Proverbs and Kohelet/Ecclesiastes did. Sukkot is the festival of transience and simcha, reminding us that the true staying power of happiness is found in wisdom.