Psalm 55:21 in the World English Bible
His mouth was smooth as butter, but his heart was war. His words were softer than oil, yet they were drawn swords.
Context
20 He hath put forth his hands against such as be at peace with him: he hath broken his covenant.
21 The words of his mouth were smoother than butter, but war was in his heart: his words were softer than oil, yet were they drawn swords.
22 Cast thy burden upon the LORD, and he shall sustain thee: he shall never suffer the righteous to be moved.