Matthew 15:11, 17-19

It is not what enters into the mouth that defiles the man, but what proceeds out of the mouth, this defiles the man.”

Do you not understand that everything that goes into the mouth passes into the stomach, and is eliminated? But the things that proceed out of the mouth come from the heart, and those defile the man. For out of the heart come evil thoughts, murders, adulteries, fornications, thefts, false witness, slanders.