וְשָׂנֵ֤אתִֽי אֲנִי֙ אֶת־כָּל־עֲמָלִ֔י שֶׁאֲנִ֥י עָמֵ֖ל תַּ֣חַת הַשָּׁ֑מֶשׁ שֶׁ֣אַנִּיחֶ֔נּוּ לָאָדָ֖ם שֶׁיִּהְיֶ֥ה אַחֲרָֽי׃
Yo asimismo aborrecí todo mi trabajo que había puesto por obra debajo del sol; el cual dejaré á otro que vendrá después de mí.
Rashi
Under the sun. תַּחַת [meaning] in exchange for the Torah.2See above 2:18.
From David to Destruction
Finally, Divrei HaYamim II 11 describes Rechav'am's successful efforts to build and fortify the cities of Yehudah. He even manages to oversee two Shevatim defecting from the northern secession and rejoining his kingdom, Binyamin and Levi. All in all, it seems that Rechav'am is not at all a fool. Indeed, it would be utterly shocking to find the son of Shlomo Hamelech to be a complete fool. Kohelet 2:18-19, which speaks of the author’s son as a fool, speaks hypothetically and does not describe reality, as noted by Da’at Mikra ad. loc.