Ecclesiastes 5:2

5:2 Do not be rash with your mouth or hasty in your heart to bring up a matter before God,

for God is in heaven and you are on earth!

Therefore, let your words be few.

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.