Parallel
Ecclesiastes 2:19
Brenton's English Septuagint · Berean Standard Bible
And who knows whether he will be a wise [man] or a fool? and whether he will have power over all my labour in which I laboured, and wherein I grew wise under the sun? this is also vanity.
And who knows whether that man will be wise or foolish? Yet he will take over all the labor at which I have worked skillfully under the sun. This too is futile.