Ecclesiastes 8:16 - 8:17
16 When I gave my heart to know wisdom and to see the endeavor which has been done on the earth (even though one never sees sleep with his eyes day or night), 17 and I saw every work of God, I concluded that man cannot find out the work which has been done under the sun. Even though man should seek laboriously, he will not find it out; and though the wise man should say, “I know,” he cannot find it out.