Ecclesiastes 2:20

2:20 So I began to despair about all the fruit of my labor

for which I worked so hard on earth.

Ecclesiastes 7:3

7:3 Sorrow is better than laughter,

because sober reflection is good for the heart.

Ecclesiastes 8:11

8:11 When a sentence is not executed at once against a crime,

the human heart is encouraged to do evil.