Ecclesiastes 2:11

Then I looked on all the works that my hands had wrought, and
on the labour that I had laboured to do
He had looked at them, and on them, over and over again, and had taken pleasure therein; but now he sits down and enters into a serious consideration of them, what prodigious expenses he had been at; what care and thought, what toil and labour of mind, he had taken in contriving, designing, and bringing these works to perfection; what pleasure and delight he had found in them, and what happiness upon the whole arose from them: he now passes his judgment, and gives his sentiments concerning these things, having had it in his power to make himself master of everything delightful, which he did; was a competent judge, and thoroughly qualified to give a just estimate of matters; and it is as follows; and, behold, all [was] vanity and vexation of spirit;
nothing solid and substantial in the whole; no true pleasure and real joy, and no satisfaction or happiness in that pleasure; these pleasing things perished with the using, and the pleasure of them faded and died in the enjoyment of them; and instead of yielding solid delight, only proved vexations, because the pleasure was so soon over, and left a thirst for more, and what was not to be had; at most and best, only the outward senses were fed, the mind not at all improved, nor the heart made better, and much less contented; it was only pleasing the fancy and imagination, and feeding on wind; and [there was] no profit under the sun;
by those things; to improve and satisfy the mind of man, to raise him to true happiness, to be of any service to him in the hour of death, or fit him for an eternal world. Alshech interprets the labour mentioned in this text of the labour of the law, which brings no reward to a man in this world.