3 Having then put away all these things, by this His excellent legislation, He added yet another charge, saying,
“Give not that which is holy unto the dogs, neither cast ye your pearls before swine.”
“Yet surely further on,” it will be said, He commanded, “What you have heard in the ear, that preach ye upon the housetops.” But this is in no wise contrary to the former. For neither in that place did He simply command to tell all men, but to whom it should be spoken, to them He bade speak with freedom. And by “dogs” here He figuratively described them that are living in incurable ungodliness, and affording no hope of change for the better; and by “swine,” them that abide continually in an unchaste life, all of whom He has pronounced unworthy of hearing such things. Paul also, it may be observed, declared this when He said, “But a natural man receives not the things of the Spirit, for they are foolishness unto him.” And in many other places too He says that corruption of life is the cause of men's not receiving the more perfect doctrines. Wherefore He commands not to open the doors to them; for indeed they become more insolent after learning. For as to the well-disposed and intelligent, things appear venerable when revealed, so to the insensible, when they are unknown rather. Since then from their nature, they are not able to learn them, “let the thing be hidden,” says He, “that at least for ignorance they may reverence them. For neither does the swine know at all what a pearl is. Therefore since he knows not, neither let him see it, lest he trample under foot what he knows not.”
For nothing results, beyond greater mischief to them that are so disposed when they hear; for both the holy things are profaned by them, not knowing what they are; and they are the more lifted up and armed against us. For this is meant by, “lest they trample them under their feet, and turn again and rend you.”
Nay, “surely,” says one, “they ought to be so strong as to remain equally impregnable after men's learning them, and not to yield to other people occasions against us.” But it is not the things that yield it, but that these men are swine; even as when the pearl is trampled under foot, it is not so trampled, because it is really contemptible, but because it fell among swine.
And full well did He say, “turn again and rend you:” for they feign gentleness, so as to be taught: then after they have learned, quite changing from one sort to another, they jeer, mock and deride us, as deceived persons. Therefore Paul also said to Timothy, “Of whom also beware; for he has greatly withstood our words;” and again in another place, “From such turn away,” and, “A man that is an heretic, after the first and second admonition, reject.”
It is not, you see, that those truths furnish them with armor, but they become fools in this way of their own accord, being filled with more willfulness. On this account it is no small gain for them to abide in ignorance, for so they are not such entire scorners. But if they learn, the mischief is twofold. For neither will they themselves be at all profited thereby, but rather the more damaged, and to you they will cause endless difficulties.
Let them hearken, who shamelessly associate with all, and make the awful things contemptible. For the mysteries we too therefore celebrate with closed doors, and keep out the uninitiated, not for any weakness of which we have convicted our rites, but because the many are as yet imperfectly prepared for them. For this very reason He Himself also discoursed much unto the Jews in parables, “because they seeing saw not.” For this, Paul likewise commanded “to know how we ought to answer every man.”
4. “Ask, and it shall be given you; seek, and you shall find; knock, and it shall be opened unto you.”
For inasmuch as He had enjoined things great and marvellous, and had commanded men to be superior to all their passions, and had led them up to Heaven itself, and had enjoined them to strive after the resemblance, not of angels and archangels, but (as far as was possible) of the very Lord of all; and had bidden His disciples not only themselves duly to perform all this, but also to correct others, and to distinguish between the evil and them that are not such, the dogs and them that are not dogs (although there be much that is hidden in men):— that they might not say, “these things are grievous and intolerable,” (for indeed in the sequel Peter did utter some such things, saying, “Who can be saved?” and again, If the case of the man be so, it is not good to marry): in order therefore that they might not now likewise say so; as in the first place even by what had gone before He had proved it all to be easy, setting down many reasons one upon another, of power to persuade men: so after all He adds also the pinnacle of all facility, devising as no ordinary relief to our toils, the assistance derived from persevering prayers. Thus, we are not ourselves, says He, to strive alone, but also to invoke the help from above: and it will surely come and be present with us, and will aid us in our struggles, and make all easy. Therefore He both commanded us to ask, and pledged Himself to the giving.
However, not simply to ask did He command us, but with much assiduity and earnestness. For this is the meaning of “seek.” For so he that seeks, putting all things out of his mind, is taken up with that alone which is sought, and forms no idea of any of the persons present. And this which I am saying they know, as many as have lost either gold, or servants, and are seeking diligently after them.
By “seeking,” then, He declared this; by “knocking,” that we approach with earnestness and a glowing mind.
Despond not therefore, O man, nor show less of zeal about virtue, than they do of desire for wealth. For things of that kind you have often sought and not found, but nevertheless, though thou know this, that you are not sure to find them, you put in motion every mode of search; but here, although having a promise that you will surely receive, thou dost not show even the smallest part of that earnestness. And if you dost not receive straightway, do not even thus despair. For to this end He said, “knock,” to signify that even if He should not straightway open the door, we are to continue there.
Source: Homilies on the Gospel of St. Matthew (New Advent)