The heart is the source of moral defilement.

²⁰And he said, That which cometh out of the man, that defileth the man.

²¹For from within, out of the heart of men, proceed evil thoughts, adulteries, fornications, murders,

²²Thefts, covetousness, wickedness, deceit, lasciviousness, an evil eye, blasphemy, pride, foolishness:

²³All these evil things come from within, and defile the man.

¹⁸But those things which proceed out of the mouth come forth from the heart; and they defile the man.

¹⁹For out of the heart proceed evil thoughts, murders, adulteries, fornications, thefts, false witness, blasphemies:

²⁰These are the things which defile a man: but to eat with unwashen hands defileth not a man.