Again, I considered all travail, and every right work, that for this a man is envied of his neighbour. This is also vanity and vexation of spirit.
Every right work ... for this a man is envied - rather (as note, Ecclesiastes 2:21, "equity," prosperity), prosperous. Prosperity, which men so much covet, is the very source of provoking oppression (Ecclesiastes 4:1) and "envy," so far is it from constituting the chief good. Hengstenberg translates skill.
Of his neighbour. It aggravates the baseness of the envy, that it is on the part of one's own neighbour. So the tenth commandment.
This is also vanity. Even success by skill brings no solid satisfaction.