Cross reference
Ecclesiastes 2:12
12 And I turned to see wisdom, and madness, and folly, but what `is' the man who cometh after the king? that which `is' already -- they have done it!
Ecclesiastes 1:17
17 And I give my heart to know wisdom, and to know madness and folly: I have known that even this `is' vexation of spirit;
Ecclesiastes 7:25
25 I have turned round, also my heart, to know and to search, and to seek out wisdom, and reason, and to know the wrong of folly, and of foolishness the madness.
Ecclesiastes 1:9-10
9 What `is' that which hath been? it `is' that which is, and what `is' that which hath been done? it `is' that which is done, and there is not an entirely new thing under the sun.
10 There is a thing of which `one' saith: `See this, it `is' new!' already it hath been in the ages that were before us!