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.
John 4:14
but whoever drinks of the water that I shall give him will never thirst. The water that I shall give him will become in him a spring of water welling up to eternal life."
John 7:38-39
He who believes in me, as the Scripture has said, out of his heart will flow rivers of living water."
Colossians 3:16
Let the word of Christ dwell in you richly, teach and admonish one another with all wisdom, and sing psalms and hymns and spiritual songs with thankfulness in your hearts to God.
Colossians 4:6
Let your speech always be full of grace, seasoned with salt, so that you may know how you ought to answer everyone.