10. Part II begins here. Since man's toils are vain, what is the chief good? (Ec 6:12). The answer is contained in the rest of the book.
      That which hath been--man's various circumstances
      is named already--not only has existed, Ec 1:9; 3:15, but has received its just name, "vanity," long ago,
      and it is known that it--vanity
      is man--Hebrew, "Adam," equivalent to man "of red dust," as his Creator appropriately named him from his frailty.
      neither may he contend, &c.-- (Ro 9:20).

JFB.