Psalms 55:21
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. 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.
Speech can sound smooth, gentle, friendly, and pleasing while covering a hostile and deceitful heart that intends and plans harm. Outward professions of sympathy, unity, and openness can hide secret efforts to injure others and to work against those the speakers claim to support.
Slander operates by smooth, persuasive, honeyed speech that conceals hostility and poison and hides a curse beneath its softness. Its words still wound like weapons, even while they sound soft. The tongue behind such speech shifts between sweetness and bitterness and spreads its attack wherever it can reach.
Pleasant speech of this kind does not match inward purpose or outward conduct when it comes from those who profess to serve God while cherishing sin and following Satan's devices.