Matthew 12:34
O ye generations of vipers, how are you, being evil, able to speak good things? for out of the abundance of the heart the mouth speaks.
John 4:14
but whosoever may drink of the water that I shall give to him shall never thirst; but the water which I shall give to him shall be in him a well of water springing up unto eternal life.
John 7:38-39
The one believing on me, as the Scripture said, out of his heart shall flow rivers of living water.
Colossians 3:16
Let the word of God dwell in you richly, teaching and admonishing one another, in all wisdom, in psalms, hymns, spiritual songs, with grace making melody in your hearts to God;
Colossians 4:6
Let your word be always with grace, seasoned with salt, that you may know how it behooves you to answer each one.