To the conductor, a Psalm of David. I said, "I will guard my ways." This is what the scripture says (Proverbs 15:1): "A soft answer turns away wrath, but a harsh word stirs up anger." The language of evil speech is more severe than idol worship, for when the Israelites sinned in the desert, they were not punished until they sinned with their mouths.
And so it says (Deuteronomy 1:34): "The Lord heard your words," and it says (Numbers 14:28): "As I live, says the Lord, as you have spoken in my hearing, so I will do to you." (Malachi 2:17) "You have wearied the Lord with your words." It says "your words," which means only with your words. And so it says (Isaiah 3:8): "For Jerusalem has stumbled, and Judah has fallen." (Jeremiah 12:8) "My heritage has become to me like a lion in the forest, she has raised her voice against me."
But is her voice one of hatred? Doesn't her voice express love as well? As it says (Song of Songs 2:14): "Let me hear your voice," which means, both your beloved voice and your hateful voice. Therefore, say now (Proverbs 18:21): "Death and life are in the power of the tongue."