Proverbs 26:23-25

Like a [common] clay vessel covered with the silver dross [making it appear silver when it has no real value] Are burning lips [murmuring manipulative words] and a wicked heart. He who hates, disguises it with his lips, But he stores up deceit in his heart. When he speaks graciously and kindly [to conceal his malice], do not trust him, For seven abominations are in his heart.