Ecclesiastes 8:16

When I applied mine heart to know wisdom
The nature and causes of things; the wisdom of God in his providence, and the grounds and reasons of his various dispensations towards the children of men: the Targum interprets it, the wisdom of the law; and to see the business that is done upon the earth;
either the business of Providence, in dealing so unequally with the righteous and the wicked, before observed; and which is a business very afflictive and distressing for curious persons to look into, not being able to account for it: or the labour and toil of men to get wealth and riches, and to find happiness in them; (for also [there is that] neither day nor night seeth sleep with his
eyes);
or has any sleep in his eyes, through his eager pursuit after worldly things, or, however, has but little; he rises early and sits up late at his business, so close and diligent is he at it, so industrious to obtain riches, imagining a happiness in them there is not: or else this describes persons curious and inquisitive into the affairs of Providence, and the reasons of them; who give themselves no rest, day nor night, being so intent upon their studies of this kind; and perhaps the wise man may design himself.