17 And I applied my heart to know wisdom and to know ^qmadness and folly. I perceived that this also is but a striving after wind.

9 All this I observed while ⁱapplying my heart to all that is done under the sun, when man had power over man to his hurt.

16 When I applied my heart to know wisdom, and to see the business that is done on earth, how neither day nor night do one’s eyes see sleep,