Ecclesiastes 1:12-14

12 I the Preacher was king over Israel in Jerusalem.

13 And I gave my heart to seek and search out by wisdom concerning all things that are done under heaven: this sore travail has God given to the sons of man to be exercised therewith.

14 I have seen all the works that are done under the sun; and, behold, all is vanity and vexation of spirit.