John Chrysostom — as excerpted in the Catena Aurea on Matthew 15:15-20

“For the things which are of the heart, remain within a man, and defile him in going out of him, as well as in abiding in him; yea, more in going out of him; wherefore He adds, Out of the heart proceed evil thoughts; He gives these the first place, because this was the very fault of the Jews, who laid snares for Him.”