Proverbs 10:20-21

10:20 What the righteous say is like the best silver,

but what the wicked think is of little value.

10:21 The teaching of the righteous feeds many,

but fools die for lack of wisdom.

Matthew 12:34

12:34 Offspring of vipers! How are you able to say anything good, since you are evil? For the mouth speaks from what fills the heart.

James 3:6

3:6 And the tongue is a fire! The tongue represents the world of wrongdoing among the parts of our bodies. It pollutes the entire body and sets fire to the course of human existence – and is set on fire by hell.