Matthew 12:34-35

Ye broods of vipers, how can ye speak good things, yourselves being wicked? for out of the abundance of the heart the mouth speaketh.

Colossians 3:16

Let the word of Christ dwell in you richly in all wisdom, teaching and admonishing yourselves in psalms, and hymns, and spiritual canticles, singing with grace in your heart unto the Lord.

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
Ye broods of vipers, how can ye speak good things, yourselves being wicked? for out of the abundance of the heart the mouth speaketh.
Colossians 3:16
Let the word of Christ dwell in you richly in all wisdom, teaching and admonishing yourselves in psalms, and hymns, and spiritual canticles, singing with grace in your heart unto the Lord.