Jeremiah 9:3-5, 8

And they bend their tongues like their bow for lies: but they are not valiant for the truth upon the earth; for they proceed from evil to evil, and they know not me, saith the LORD. Take ye heed every one of his neighbour, and trust ye not in any brother: for every brother will utterly supplant, and every neighbour will walk with slanders. And they will deceive every one his neighbour, and will not speak the truth: they have taught their tongue to speak lies, and weary themselves to commit iniquity.

Their tongue is as an arrow shot out; it speaketh deceit: one speaketh peaceably to his neighbour with his mouth, but in heart he layeth his wait.