Job 28:3
Man puts an end to the darkness; he probes the farthest recesses for ore in deepest darkness.

Ecclesiastes 1:17
So I set my mind to know wisdom and madness and folly; I learned that this, too, is a pursuit of the wind.

Ecclesiastes 2:23
Indeed, all his days are filled with grief, and his task is sorrowful; even at night, his mind does not rest. This too is futile.

Ecclesiastes 2:26
To the man who is pleasing in His sight, He gives wisdom and knowledge and joy, but to the sinner He assigns the task of gathering and accumulating that which he will hand over to one who pleases God. This too is futile and a pursuit of the wind.

Ecclesiastes 3:10
I have seen the burden that God has laid on men to occupy them.

Ecclesiastes 3:11
He has made everything beautiful in its time. He has also set eternity in the hearts of men, yet they cannot fathom the work God has done from beginning to end.

Ecclesiastes 4:8
There is a man all alone, without even a son or brother. And though there is no end to his labor, his eyes are still not content with his wealth: "For whom do I toil and bereave my soul of enjoyment?" This too is futile--a miserable task.

Ecclesiastes 7:25
I directed my mind to understand, to explore, to search out wisdom and explanations, and to understand the stupidity of wickedness and the folly of madness.

Ecclesiastes 8:16
When I applied my mind to know wisdom and to observe the activity that one does on the earth--though his eyes do not see sleep day or night--

Ecclesiastes 8:17
I saw every work of God, and that a man is unable to comprehend the work that is done under the sun. Despite his efforts to search it out, he cannot find its meaning; even if the wise man claims to know, he is unable to comprehend.

Ecclesiastes 11:5
As you do not know the path of the wind, or how the bones are formed in a mother's womb, so you cannot understand the work of God, the Maker of all things.