19 And who knoweth whether he shall be a wise man or a fool? yet shall he have rule over all my labour wherein I have laboured, and wherein I have shewed myself wise under the sun. This is also vanity.
and no one knows whether he will be wise or foolishly clever, and yet he will have power over all my toil at which I have moiled, and done so wisely in this hot work-day world: another instance this of evanescence.
(19.) And who knows (equivalent to ‘no-body does know’) whether the wise (with the article, meaning one who belongs to this class, and who will really act wisely) or a fool? (סכל——that is, a wisely-foolish person, one whose wisdom will prove a mistake according to the meaning of this word, see [chapter ii. 3], references.; and will use this power provided to his hand either amiss, or so as to defeat the end the wise man had in view) and he has power (שלט, a favourite word of Koheleth’s; the exact meaning of this term may be found in Psalm cxix. 130) in all my toil which I have toiled at, and which also I have made myself wise in (i.e. spent my pains wisely in) under the sun: besides this is vanity (or, as we should say, ‘moreover this is another instance of vanity or evanescence’).
20 Therefore I went about to cause my heart to despair of all the labour which I took under the sun.
So then I came round to the conclusion that I must bid farewell to any hope of satisfaction from anything I had toiled at in this work-day world;
(20.) I turned round then, I myself, to cause to despair with respect to my heart (יאש, occurs 1 Samuel xxvii. 1, where the word is used of Saul giving up the search for David in despair) over the toil which I toiled at under the sun.