Matthew 15:18 in the King James Version
But those things which proceed out of the mouth come forth from the heart; and they defile the man.
Context
17 Don’t you understand that whatever goes into the mouth passes into the belly and then out of the body?
18 But the things which proceed out of the mouth come out of the heart, and they defile the man.
19 For out of the heart come evil thoughts, murders, adulteries, sexual sins, thefts, false testimony, and blasphemies.