Adam Clarke on Ecclesiastes 2:2

I said of laughter, It is mad - Literally "To laughter I said, O mad one! and to mirth, What is this one doing?"

Solomon does not speak here of a sober enjoyment of the things of this world, but of intemperate pleasure, whose two attendants, laughter and mirth are introduced by a beautiful prosopopoeia as two persons; and the contemptuous manner wherewith he treats them has something remarkably striking. He tells the former to her face that she is mad; but as to the latter, he thinks her so much beneath his notice, that he only points at her, and instantly turns his back.