Matthew 12:34-35

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.

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;

Treasury of Scripture Knowledge

Summary

The heart of the wise teacheth his mouth, and addeth learning to his lips.

Bible References

Heart

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.
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;