Ecclesiastes 2:12

And I turned to see wisdom, madness, and folly: for what the man that shall come after the king? with those things they did already.

Ecclesiastes 1:17

And I will give my heart to know wisdom, and the knowledge of praise and understanding: I knew this also it is the striving of the spirit

Ecclesiastes 7:25

I went round about, I and my heart., to know, and to examine, and to search out wisdom and understanding, and to know the injustice of folly, and the folly of wickedness:

Ecclesiastes 1:9-10

What was, that shall be; and what was done, that shall be done: and not anything new under the sun.

Treasury of Scripture Knowledge

Summary

And I turned myself to behold wisdom, and madness, and folly: for what can the man do that cometh after the king? even that which hath been already done.

Even that which hath been already done

Bible References

I turned

Ecclesiastes 1:17
And I will give my heart to know wisdom, and the knowledge of praise and understanding: I knew this also it is the striving of the spirit
Ecclesiastes 7:25
I went round about, I and my heart., to know, and to examine, and to search out wisdom and understanding, and to know the injustice of folly, and the folly of wickedness:

Even that which hath been already done

Ecclesiastes 2:25
For who shall eat, and who shall hasten forth above me?