Ernst Lohmeyer ( Lord of the Temple ) argues that Jesus’ saying on defilement in Mark 7 (=Matthew 15) “transfers the whole question of purity from the plant of material externals to that of man’s inner self . . . . there emerges in unmistakable superiority the inner world of the human heart which alone is able to make a man holy or unholy, clean or unclean.” He goes on to admit that “‘what comes out of the mouth’ denotes everything that lodges in the heart and demands expression,” but he believes Jesus’ emphasis is on an inner purity.

This is not what Jesus says, however. He talks about the source of impurity (outside v. inside) and the direction (outside-in, inside-out) but he doesn’t say that defilement is not simply an issue of the inner man. What defiles, in fact, is not what is within but what originates within and flows out . Intriguingly, Jesus sees even “evil thoughts” as realities that “come out” of the heart, and his list of defilements puts these on a par with external, material acts. Perhaps in the light of Matthew 15:18, we should understand defiling evil thoughts as those that find expression in words.

But Jesus doesn’t indicate a possibility of an impurity that remains tightly enclosed within the heart, and he likely doesn’t envision a tightly enclosed purity of heart either. Defilements are movements, flows, springs; thoughts and words and actions that comes from the heart but don’t remain there.