Ecclesiastes 10:12-13
Words and Works of Wise Men and Fools
10:12 The words of a wise person win him favor,
but the words of a fool are self-destructive.
10:13 At the beginning his words are foolish
and at the end his talk is wicked madness,
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.