Matthew 12:34-35

Offspring of vipers, how can you, being evil, speak good things? For out of the abundance of the heart the mouth speaks.

Colossians 3:16

Let the word of Christ dwell in you richly, teaching with all wisdom, and admonishing one another, with psalms, hymns, spiritual songs, singing with grace 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
Offspring of vipers, how can you, being evil, speak good things? For out of the abundance of the heart the mouth speaks.
Colossians 3:16
Let the word of Christ dwell in you richly, teaching with all wisdom, and admonishing one another, with psalms, hymns, spiritual songs, singing with grace in your hearts to God,