NOTES for Ecc 5:11
In Ecclesiastes, reflections on the meaning of the foundations of existence smoothly pass into reflections on the principles on which everyday life is based, and often practical advice about being careful in one's words is followed by reflections we would call socially critical. Here the words about vanity of vanities begin to sound somewhat special, especially since the labor of a person who has no surplus is not called vanity here. The laborer, whether he eats little or much, is not familiar with the satiety of the excessively rich; and often the companion of satiety is the feeling of meaninglessness, the vanity of everything that is happening and surrounding him.