Pseudo-Chrysostom — as excerpted in the Catena Aurea on Mark 7:14-23

“(Vict. Ant. e Cat. in Marc.) Again He subjoins, If any man have ears to hear, let him hear. For He had not clearly shewn them, what those things are which proceed out of a man, and defile a man; and on account of this saying, the Apostles thought that the foregoing discourse of the Lord implied some other deep thing; wherefore there follows: And when he was entered into the house from the people, his disciples asked him concerning the parable; they called it parable, because it was not clear.”