For all his days are full of sorrow, and his work is a vexation. Even in the night his heart does not rest. This also is vanity.
Business is a thing that wise men have pleasure in. They are in their element when they are in their business, and complain if they be out of business. They may sometimes be tired with their business, but they are not weary of it, nor willing to leave it off.
Commenting on Ecclesiastes 2:17-26
For all his days are sorrows, and his travail grief,.... All his days are full of sorrows, of a variety of them; and all his affairs and transactions of life are attended with grief and trouble; not only the days of old age are evil ones, in which he can take no pleasure; or those times which exceed the common age of man, when he...
The only fruit he has is, not only sorrows in his days, but all his days are sorrows, and his travail (not only has griefs connected with it, but is itself), grief.