Jerome
Catena Aurea · Matthäusevangelium 12
Either make the tree good, and his fruit good; or else make the tree corrupt, and his fruit corrupt: for the tree is known by his fruit. O generation of vipers, how can ye, being evil, speak good things? for out of the abundance of the heart the mouth speaketh. A good man out of the good treasure of the heart bringeth forth good things: and an evil man out of the evil treasure bringeth forth evil things.
What He says, The good man out of the good treasure of his heart, & c. is either pointed against the Jews, that seeing they blasphemed God, what treasure in their heart must that be out of which such blasphemy proceeded; or it is connected with what had gone before, that like as a good man cannot bring forth evil things, nor an evil man good things, so Christ cannot do evil works, nor the Devil good works.