You can usually look at something and determine if it’s unclean. For example, dishes, clothes, vehicles, places, hair, and even physical bodies. These are things that you can see. However, an impure heart which is not seen feeds what comes out of the mouth which is seen and heard. Take careful responsibility to guard and protect your heart from defilement and pollution. Remember, God hides His Word in your heart and this is what He alone sees and judges.