From the early Church Fathers to now.
13 Patristic · 2 Medieval
“Give not that which is holy to dogs; neither cast ye your pearls before swine, lest perhaps they trample them under their feet, and turning upon you, they tear you.”
“And to those that are right-minded and have understanding, when revealed they appear good; but to those without understanding, they seem to be more deserving reverence because they are not understood.”
“Well is that said, Lest they turn; for they feign meekness that they may learn; and when they have learned, they attack.”
“(ubi sup.) Because the simplicity to which He had been directing in the foregoing precepts might lead some wrongly to conclude that it was equally wrong to hide the truth as to utter what was false, He well adds, Give not that which is holy to the dogs, and cast not your pearls before swine.”
“(Serm. in Mont. ii. 20.) Let us see now what is the holy thing, what are the dogs, what the pearls, what the swine? The holy thing is all that it were impiety to corrupt; a sin which may be committed by the will, though the thing itself be undone. The pearls are all spiritual things that are to be highly esteemed. Thus though one and the same thing may be called both the holy thing and a pearl, yet it is called holy because it is not to be corrupted; and called a pearl because it is not to be contemned.”
“(ubi sup.) The dogs are those that assault the truth; the swine we may not unsuitably take for those that despise the truth. Therefore because dogs leap forth to rend in pieces, and what they rend, suffer not to continue whole, He said, Give not that which is holy to the dogs; because they strive to the utmost of their power to destroy the truth. The swine though they do not assault by biting as dogs, yet do they defile by trampling upon, and therefore He said, Cast not your pearls before swine.”
“(ubi sup.) That which is despised is said to be trodden under foot: hence it is said, Lest perchance they tread them under foot.”
“(ubi sup.) That which follows, Turn again and rend you, He means not the pearls themselves, for these they tread under foot, and when they turn again that they may hear something further, then they rend him by whom the pearls on which they had trode had been cast. For you will not easily find what will please him who has despised things got by great toil. Whoever then undertake to teach such, I see not how they shall not be trode upon and rent by those they teach.”
“(ubi sup.) We must be careful therefore not to explain ought to him who does not receive it; for men the rather seek that which is hidden than that which is opened. He either attacks from ferocity as a dog, or overlooks from stupidity as swine. But it does not follow that if the truth be kept hid, falsehood is uttered. The Lord Himself who never spoke falsely, yet sometimes concealed the truth, as in that, I have yet many things to say unto you, the which ye are not now able to bear. (John 16:12.) But if any is unable to receive these things because of his filthiness, we must first cleanse him as far as lays in our power either by word or deed. But in that the Lord is found to have said some things which many who heard Him did not receive, but either rejected or contemned them, we are not to think that therein He gave the holy thing to the dogs, or cast His pearls before swine. He gave to those who were able to receive, and who were in the company, whom it was not fit should be neglected for the uncleanness of the rest. And though those who tempted Him might perish in those answers which He gave to them, yet those who could receive them by occasion of these inquiries heard many useful things. He therefore who knows what should be answered ought to make answer, for their sakes at least who might fall into despair should they think that the question proposed is one that cannot be answered. But this only in the case of such matters as pertain to instruction of salvation; of things superfluous or harmful nothing should be said; but it should then be explained for what reason we ought not to make answer in such points to the enquirer.”
“Or; The dogs are returned to their vomit; the swine not yet returned, but wallowing in the mire of vices.”
“Otherwise; The Lord had commanded us to love our enemies, and to do good to those that sin against us. That from this Priests might not think themselves obliged to communicate also the things of God to such, He checked any such thought saying, Give not that which is holy to the dogs; as much as to say, I have bid you love your enemies, and do them good out of your temporal goods, but not out of My spiritual goods, without distinction. For they are your brethren by nature but not by faith, and God gives the good things of this life equally to the worthy and the unworthy, but not so spiritual graces.”
“Otherwise; That which is holy denotes baptism, the grace of Christ’s body, and the like; but the mysteries of the truth are intended by the pearls. For as pearls are inclosed in shells, and such in the deeps of the sea, so the divine mysteries inclosed in words are lodged in the deep meaning of Holy Scripture.”
“Otherwise; The dog and the swine are unclean animals; the dog indeed in every respect, as he neither chews the cud, nor divides the hoof; but swine in one respect only, seeing they divide the hoof, though they do not chew the cud. Hence I think that we are to understand by the dog, the Gentiles who are altogether unclean, both in their life, and in their faith; but by the swine are to be understood heretics, because they seem to call upon the name of the Lord. Give not therefore that which is holy to the dogs, for that baptism and the other sacraments are not to be given but to them that have the faith. In like manner the mysteries of the truth, that is, the pearls, are not to be given but to such as desire the truth and live with human reason. If then you cast them to the swine, that is, to such as are grovelling in impurity of life, they do not understand their preciousness, but value them like to other worldly fables, and tread them under foot with their carnal life.”
“(interlin.) He says, Lest perchance, because it may be that they will wisely turn from their uncleannessa.”
“Or; The swine not only trample upon the pearls by their carnal life, but after a little they turn, and by disobedience rend those who offend them. Yea often when offended they bring false accusation against them as sowers of new dogmas. The dogs also having trode upon holy things by their impure actions, by their disputings rend the preacher of truth.”
“With good reason He forbade pearls to be given to swine. For if they are not to be set before swine that are the less unclean, how much more are they to be withheld from dogs that are so much more unclean. But respecting the giving that which is holy, we cannot hold the same opinion; seeing we often give the benediction to Christians who live as the brutes; and that not because they deserve to receive it, but lest perchance being more grievously offended they should perish utterly.”
The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.