Eclesiastes 10:20

20 Do not revile the king even in your thoughts, or curse the rich in your bedroom, because a bird in the sky may carry your words, and a bird on the wing may report what you say.

20 Say not a curse against the king, even in your thoughts; and even secretly say not a curse against the man of wealth; because a bird of the air will take the voice, and that which has wings will give news of it.