“For out of the abundance of the heart the mouth speaks” (Matthew 12:34, NKJV). Jesus isn’t offering a general observation about speech here. He’s naming a direct connection: what fills the heart is what eventually comes out of the mouth.
This means our words are actually useful data about our own hearts, more honest sometimes than our own self-assessment.
If sharp, critical, or anxious words have been coming out more often lately, this verse suggests looking upstream, at what’s actually filling the heart, rather than just trying to filter the words themselves.
What has your mouth been revealing lately about what’s filling your heart, whether or not you meant to show it?