Ecclesiastes 2:10-11; Ecclesiastes 2:17; Ecclesiastes 2:24-26

10 And whatsoever mine eyes desired I kept not from them, I withheld not my heart from any joy; for my heart rejoiced in all my labour: and this was my portion of all my labour. 11 Then I looked on all the works that my hands had wrought, and on the labour that I had laboured to do: and, behold, all was vanity and vexation of spirit, and there was no profit under the sun.
17 Therefore I hated life; because the work that is wrought under the sun is grievous unto me: for all is vanity and vexation of spirit.
24 There is nothing better for a man, than that he should eat and drink, and that he should make his soul enjoy good in his labour. This also I saw, that it was from the hand of God. 25 For who can eat, or who else can hasten hereunto, more than I? 26 For God giveth to a man that is good in his sight wisdom, and knowledge, and joy: but to the sinner he giveth travail, to gather and to heap up, that he may give to him that is good before God. This also is vanity and vexation of spirit.