Ecclesiastes 8:7; Ecclesiastes 8:15; Ecclesiastes 8:17

7 Since no one knows the future, who can tell someone else what is to come?
15 So I commend the enjoyment of life, because there is nothing better for a person under the sun than to eat and drink and be glad. Then joy will accompany them in their toil all the days of the life God has given them under the sun.
17 then I saw all that God has done. No one can comprehend what goes on under the sun. Despite all their efforts to search it out, no one can discover its meaning. Even if the wise claim they know, they cannot really comprehend it.