Ecclesiastes 4:4; Ecclesiastes 4:7-8

4 I saw that all labor and all skillful work is due to a man's jealousy of his friend. This too is futile and a pursuit of the wind.

7 Again, I saw futility under the sun:

8 There is a person without a companion, without even a son or brother, and though there is no end to all his struggles, his eyes are still not content with riches. "So who am I struggling for," [he asks,] "and depriving myself from good?" This too is futile and a miserable task.