Ecclesiastes 4:4; Ecclesiastes 4:7-8

4 Again, I considered all labor, and every right work, that for this a man is envied by his neighbor. This [is] also vanity and vexation of spirit.

7 Then I returned, and I saw vanity under the sun.

8 There is one [alone], and [there is] not a second; yes, he hath neither child nor brother: yet [is there] no end of all his labor; neither is his eye satisfied with riches; neither [saith he], For whom do I labor, and bereave my soul of good? This [is] also vanity, yes, it [is] a grievous labor.