Ecclesiastes 4:4; Ecclesiastes 4:7-8

4 And I saw that the cause of all the work and of everything which is done well was man's envy of his neighbour. This again is to no purpose and a desire for wind.

7 Then I came back, and I saw an example of what is to no purpose under the sun.

8 It is one who is by himself, without a second, and without son or brother; but there is no end to all his work, and he has never enough of wealth. For whom, then, am I working and keeping myself from pleasure? This again is to no purpose, and a bitter work.