Matthew 12:34-35

"Broods of vipers! how can ye speak good things, being yourselves evil? For, out of the abundance of the heart, the mouth speaks.

Colossians 3:16

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