Matthew 12:34
You brood of vipers! how can you speak good, when you are evil? For out of the abundance of the heart the mouth speaks.
Romans 3:13-14
"Their throat is an open grave; they use their tongues to practice deceit." "The poison of asps is under their lips."
2 Corinthians 11:3
But I am afraid that just as the serpent deceived Eve by his cunning, your minds may somehow be led astray from your sincere and pure devotion to Christ.
James 3:6-8
And the tongue is a fire, a world of evil among the members of the body. The tongue corrupts our whole person, sets the whole course of our life on fire, and is itself set on fire by hell.