Ecclesiastes 4:4; Ecclesiastes 4:7-8
Again I considered all the labours of men, and I remarked that their industries are exposed to the envy of their neighbour: so in this also there is vanity, and fruitless care.
Considering I found also another vanity under the sun:
There is but one, and he hath not a second, no child, no brother, and yet he ceaseth not to labour, neither are his eyes satisfied with riches, neither doth he reflect, saying: For whom do I labour, and defraud my soul of good things? in this also is vanity, and a grievous vexation.