"Don't you see that whatever enters the mouth goes into the stomach and then out of the body? But the things that come out of the mouth come from the heart, and these make a man 'unclean.' For out of the heart come evil thoughts, murder, adultery, sexual immorality, theft, false testimony, slander."
MATTHEW 15:17-19

Above all else, guard your heart, for it is the wellspring of life.
PROVERB 4:23