Then I saw all that God has done. No one can comprehend what goes on under the sun. People toil to search it out, but no one can discover its meaning. Even if the wise claim they know, they cannot really comprehend it.
NIV
Then I saw all the work of God, that man cannot find out the work that is done under the sun--because however much a man may toil in seeking, yet he will not find it out; yes, more than that, though a wise man thinks and claims he knows, yet will he not be able to find it out. [Deut. 29:29; Rom. 11:33.]AMP
Then I beheld all the work of God, that a man cannot find out the work that is done under the sun: because though a man labour to seek it out, yet he shall not find it; yea farther; though a wise man think to know it, yet shall he not be able to find it.
KJV
For there is a proper time and procedure for every matter, though a person may be weighed down by misery.
NIV
For every purpose and matter has its [right] time and judgment, although the misery and wickedness of man lies heavily upon him [who rebels against the king].
AMP
Because to every purpose there is time and judgment, therefore the misery of man is great upon him.
KJV