Ecclesiastes 1:13
1:13 I decided to carefully and thoroughly examine
all that has been accomplished on earth.
I concluded: God has given people a burdensome task
that keeps them occupied.
Ecclesiastes 2:3
2:3 I thought deeply about the effects of indulging myself with wine
(all the while my mind was guiding me with wisdom)
and the effects of behaving foolishly,
so that I might discover what is profitable
for people to do on earth during the few days of their lives.
Ecclesiastes 10:20
10:20 Do not curse a king even in your thoughts,
and do not curse the rich while in your bedroom;
for a bird might report what you are thinking,
or some winged creature might repeat your words.