Mark 4:12

And accordingly the very thing that seemed to be spoken by Himself in secret, was in a certain sense not spoken in secret; for it was not so spoken to remain unuttered by those to whom it was spoken; but rather so in order to be preached in every possible direction. A thing therefore may be uttered at once openly, and not openly; or at the same time in secret, and yet not in secret, as it is said, "That seeing, they may see, and not see." For how "may they see," save only because it is openly, and not in secret; and again, how is it that the same parties "may not see," save that it is not openly, but in secret? Howbeit the very things which they had heard without understanding, were such as could not with justice or truth be turned into a criminal charge against Him: and as often as they tried by their questions to find something whereof to accuse Him, He gave them such replies as utterly discomfited all their plots, and left no ground for the calumnies they devised.

(Quaest. 14, in Matt.) Or else they deserved this, their not understanding, and yet this in itself was done in mercy to them, that they might know their sins, and, being converted, merit pardon.

To them therefore it was not granted to know the mysteries of the kingdom of heaven, but rather unto us, who are more ready to embrace the faith. For He hath given unto us, as being perfect wisdom, the ability "to understand parables, and the dark saying, the words of the wise, and their riddles." For parables we may say are the images not of visible objects, but rather of those cognizable by the intellect and spiritual. For that which it is impossible to see with the eyes of the body, the parable points out unto the eyes of the mind, beautifully shaping out the subtilty of things intellectual, by means of the things of sense, and which are as it were palpable to the touch.

But to those who are outside, everything is done in parables, so that seeing they may see and not perceive, and hearing they may hear and not understand, lest they turn and be forgiven their sins. It should be noted in these words of the Lord that not only what he said but also what he did were parables, that is, signs of mystical things, since it is said that those to whom everything was done in parables neither could lead what they saw and heard to understanding. For what would hinder those looking at his deeds or journeys from understanding, if something more than what is apparent to the eyes of the flesh was not intended to be spiritually understood? Therefore, to those who are outside and do not approach the feet of the Lord to receive from his teaching, everything is done in parables, both the deeds and words of the Savior, because they are neither able to recognize him as God in the things he worked with power, nor in the mysteries he preached. Therefore, they do not deserve to attain the remission of sins which is to be obtained through the grace of his faith.

(ubi sup.) To those then who are without, all things are done in parables, that is, both the actions and the words of the Saviour, because neither in those miracles which He was working, nor in those mysteries which He preached, were they able to acknowledge Him as God. Therefore they are not able to attain to the remission of their sins.

However, do you wish to know that God has given all people the ability to see what is right? Listen! "With their own eyes they look" — this is from God; "and do not see" — this is from their own wickedness; for God created them seeing, that is, understanding the good, but they do not see, closing their eyes voluntarily, so as not to turn back and be corrected, as if envying their own salvation and correction. It can also be understood this way: but to the rest I speak in parables, "so that seeing with their own eyes they do not see, and hearing with their own ears they do not understand," in order that at least for this reason they might turn back and be corrected.

For it was God Who made them to see, that is, to understand what is good. But they themselves see not, of their own will making themselves not to see, lest they should be converted and correct themselves, as if they were displeased at their own salvation. It goes on, Lest at any time they should be converted, and their sins be forgiven them.

Or we may understand in a different way His speaking to the rest in parables, that seeing they might not perceive, and hearing, not understand. For God gives sight and understanding to men who seek for them, but the rest He blinds, lest it become a greater accusation against them, that though they understood, they did not choose to do what they ought. Wherefore it goes on, Lest at any time they should be, &c.

(Vict. Ant. e Cat. in Marc.) Thus, therefore, they see and they do not see, they hear and do not understand, for their seeing and hearing comes to them from God's grace, but their seeing and not understanding comes to them from their unwillingness to receive grace, and closing their eyes, and pretending that they could not see; neither do they acquiesce in what was said, and so are not changed as to their sins by hearing and seeing, but rather are made worse.

(Vict. Ant. c Cat. in Marc.) As if He said unto them, You that are worthy to be taught all things which are fitted for teaching, shall learn the manifestation of parables; but I use parables with them who are unworthy to learn, because of their wickedness. For it was right that they who did not hold fast their obedience to that law which they had received, should not have any share in a new teaching, but should be estranged from both; for He showed by the obedience of His disciples, that, on the other hand, the others were become unworthy of mystical doctrine. But afterwards, by bringing in a voice from prophecy, He confounds their wickedness, as having been long before reproved; wherefore it goes on, that seeing they might see, and not perceive, &c. (Isa. 6:9) as if He said, that the prophecy might be fulfilled which foretells these things.