Ecclesiastes 1:13 in the King James Version
And I gave my heart to seek and search out by wisdom concerning all things that are done under heaven: this sore travail hath God given to the sons of man to be exercised therewith.
Context
12 I, the Preacher, was king over Israel in Jerusalem.
13 I applied my heart to seek and to search out by wisdom concerning all that is done under the sky. It is a heavy burden that God has given to the sons of men to be afflicted with.
14 I have seen all the works that are done under the sun; and behold, all is vanity and a chasing after wind.