Ecclesiastes 8:17

17 then I beheld all the work of God, that man cannot find out the work that is done under the sun: because however much a man labor to seek it out, yet he shall not find it; yea moreover, though a wise man think to know it, yet shall he not be able to find it.

Ecclesiastes 8:17 In-Context

15 Then I commended mirth, because a man hath no better thing under the sun, than to eat, and to drink, and to be joyful: for that shall abide with him in his labor [all] the days of his life which God hath given him under the sun.
16 When I applied my heart to know wisdom, and to see the business that is done upon the earth (for also there is that neither day nor night seeth sleep with his eyes),
17 then I beheld all the work of God, that man cannot find out the work that is done under the sun: because however much a man labor to seek it out, yet he shall not find it; yea moreover, though a wise man think to know it, yet shall he not be able to find it.
The American Standard Version is in the public domain.