This sore travail hath God given— That is to say, the fatiguing employment which God gave to the sons of men, to give evidence of himself. See the paraphrase on the 15th verse.
Related Commentaries of Ecclesiastes 1:13
Ecclesiastes 1:13
13 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.