What does Matthew 15:15 mean?

Peter is the boldest of the disciples. He is the one who asked to walk on water (Matthew 14:28). He is the one who often says what others are thinking but unwilling to speak (Mark 8:29; Luke 18:28). Every group of students needs someone like Peter: the one brave enough to introduce good questions and show the teacher what level of understanding the group has reached.

On behalf of the group, Peter asks for explanation of Jesus' comments. Earlier, Jesus had said one reason He taught in parables was their obscurity (Matthew 13:13). Since they don't grasp His current point, they seem to think He's speaking in poetic or symbolic terms. He is not.

Peter's question refers to Jesus' words in verse 11: that only what comes out of the mouth defiles, not what goes in (Matthew 15:11). The disciples had been raised to believe that what they ate absolutely could defile them, spiritually. This was the main reason for the Pharisees' manmade rule about ritual handwashing. This process sought to remove any chance that your hand may carry a speck of something ritually unclean, causing you to unknowingly break the law about eating prohibited foods.

In refuting their manmade rule, one which never appears in Scripture, Jesus seems to have taught that nothing you eat could make you unclean. A faithful Jewish person would ask, "How can this possibly be true?"