50 And shall cast them into the furnace of fire: there shall be wailing and gnashing of teeth.
[AD 407] John Chrysostom on Matthew 13:47-50
In the foregoing parables He has commended the Gospel preaching; now, that we may not trust in preaching only, nor think that faith alone is sufficient for our salvation, He adds another fearful parable, saying, Again, the kingdom of heaven is like unto a net cast into the sea.

Wherein does this parable differ from the parable of the tares? There, as here, some perish and some are saved; but there, because of their heresy of evil dogmas; in the first parable of the sower, because of their not attending to what was spoken; here, because of their evil life, because of which, though drawn by the net, that is, enjoying the knowledge of God, they cannot be saved. And when you hear that the wicked are cast away, that you may not suppose that this punishment may be risked, He adds an exposition showing its severity, saying, Thus shall it be in the end of the world; the angels shall come forth and sever the wicked from among the just, and shall cast them into the furnace of fire, there shall be wailing and gnashing of teeth. Though He elsewhere declares, that He shall separate them as a shepherd separates the sheep from the goats; He here declares, that the Angels shall do it, as also in the parable of the tares.

[AD 420] Jerome on Matthew 13:47-50
In fulfilment of that prophecy of Hieremias, who said, I will send unto you many fishers, (Jer. 6:16.) when Peter and Andrew, James and John, heard the words, Follow me, I will make you fishers of men, they put together a net for themselves formed of the Old and New Testaments, and cast it into the sea of this world, and that remains spread until this day, taking up out of the salt and bitter and whirlpools whatever falls into it, that is good men and bad; and this is that He adds, And gathered of every kind.

For when the net shall be drawn to the shore, then shall be shown the true test for separating the fishes.

For when the end of the world shall be come, then shall be shown the true test of separating the fishes, and as in a sheltered harbour the good shall be sent into the vessels of heavenly abodes, but the flame of hell shall seize the wicked to be dried up and withered.

[AD 420] Jerome on Matthew 13:47-50
[Daniel 7:2-3] "And during the night I saw in my vision, and behold, the four winds of heaven strove upon the great sea, and four great beasts were coming up out of the sea, differing from one another." The four winds of heaven I suppose to have been angelic powers to whom the principalities have been committed, in accordance with what we read in Deuteronomy: "When the Most High divided the nations and when He separated the children of Adam, He established the bounds of the peoples according to the number of the angels. For the Lord's portion is His people; Jacob is the line of His inheritance (Deuteronomy 32:8). But the sea signifies this world and the present age, overwhelmed with salty and bitter waves, in accordance with the Lord's own interpretation of the dragnet cast into the sea (Matthew 13:47-50). Hence also the sovereign of all creatures that inhabit the waters is described as a dragon, and his heads, according to David, are smitten in the sea (Psalm 74:13). And in Amos we read: "If he descends to the very depth of the sea, there will I give him over to the dragon and he shall bite him" (Amos 9:3). But as for the four beasts who came up out of the sea and were differentiated from one another, we may identify them from the angel's discourse. "These four great beasts," he says, "are four kingdoms which shall rise up from the earth." And as for the four winds which strove in the great sea, they are called winds of heaven because each one of the angels does for his realm the duty entrusted to him. This too should be noted, that the fierceness and cruelty of the kingdoms concerned are indicated by the term "beasts."

[AD 420] Jerome on Matthew 13:47-50
(Verses 47 and following) Again, the kingdom of heaven is like a fishing net that was thrown into the sea and gathered fish of every kind. When it was full, they pulled it ashore, sat down, and sorted the good fish into containers, but threw away the bad ones. This is how it will be at the end of the world: the angels will come and separate the wicked from the righteous and throw them into the fiery furnace, where there will be weeping and gnashing of teeth. This fulfills the prophecy of Jeremiah, who said, 'Behold, I will send many fishermen to you' (Jeremiah 16:16). When Peter, Andrew, James, and John, the sons of Zebedee, heard this, they followed Jesus and became fishers of men (Matthew 4:19). They wove together a net of gospel teachings from the old and new testament and cast it into the sea of this world, which even to this day stretches in the midst of waves, capturing whatever falls into it from the salty and bitter depths, both good and bad people, and the best and worst fish. But when the consummation and end of the world comes, as he explains more clearly below, then the fishing net will be drawn to the shore: then the true judgment of separating the fish will be displayed, and as if in a very calm harbor, the good will be placed in the vessels of celestial mansions: but the wicked will be received to be burned and dried up by the flame of hell.

[AD 604] Gregory the Dialogist on Matthew 13:47-50
(Hom. in Ev. xi. 4.) Or otherwise; The Holy Church is likened to a net, because it is given into the hands of fishers, and by it each man is drawn into the heavenly kingdom out of the waves of this present world, that he should not be drowned in the depth of eternal death. This net gathers of every kind of fishes, because the wise and the foolish, the free and the slave, the rich and the poor, the strong and the weak, are called to forgiveness of sin; it is then fully filled when in the end of all things the sum of the human race is completed; as it follows, Which, when it was filled, they drew out, and sitting down on the shore gathered the good into vessels, but the bad they cast away. For as the sea signifies the world, so the sea shore signifies the end of the world; and as the good are gathered into vessels, but the bad cast away, so each man is received into eternal abodes, while the reprobate having lost the light of the inward kingdom are cast forth into outer darkness. But now the net of faith holds good and bad mingled together in one; but the shore shall discover what the net of the Church has brought to land.

(ubi sup.) To fear becomes us here, rather than to expound for the torments of sinners are pronounced in plain terms, that none might plead his ignorance, should eternal punishment be threatened in obscure sayings.

[AD 253] Origen of Alexandria on Matthew 13:50
And those who attended to the net that was cast into the sea are Jesus Christ, the master of the net, and “the angels who came and ministered to him.” It is not until the net is filled full that they will draw it up from the sea and carry it to the shore beyond the sea—namely, to things beyond this life—but not until the “fullness of the Gentiles” has been drawn into it. But when that fullness has come, then they draw it up from things here below and carry it to what is figuratively called the shore. There it will be the work of those who have drawn it up to sit by the shore, there to settle themselves in order that they may put each of the good fish in its own proper place, into the right vessel. But they will cast outside those that are of an opposite character and are called bad. By “outside” is meant the furnace of fire, as the Savior interpreted it, saying, “So shall it be at the consummation of the age. The angels shall come forth and separate the wicked from among the righteous and shall cast them into the furnace of fire.” Only it must be observed that we are already taught by the parable of the tares and the other similitudes set forth that the angels are to be entrusted with the power to distinguish and separate the evil from the righteous. For it is said above, “The Son of Man shall send his angels, and they shall gather out of his kingdom all things that cause stumbling, and those who do iniquity, and shall cast them into the furnace of fire. There shall be the weeping and gnashing of teeth.” But here it is said, “The angels shall come forth and sever the wicked from among the righteous and shall cast them into the furnace of fire.”

[AD 407] John Chrysostom on Matthew 13:50
And this parable He interprets without so much as being asked, but of His own motion He explained it by one part of it, and increased their awe. For lest, on being told, They cast the bad away, you should suppose that ruin to be without danger; by His interpretation He signified the punishment, saying, They will cast them into the furnace. Matthew 13:50 And He declared the gnashing of teeth, and the anguish, that it is unspeakable.

Do you see how many are the ways of destruction? By the rock, by the thorns, by the wayside, by the tares, by the net. Not without reason therefore did He say, Broad is the way that leads to destruction, and many there be which go away by it. Matthew 7:13
[AD 1107] Theophylact of Ohrid on Matthew 13:50
. Fearful is this parable, for it shows that though we believe, if we do not lead a good life we shall be cast into the fire. The net is the teaching of the fishermen apostles, woven from miracles and the prophets’ testimonies. For what the apostles taught, they confirmed with miracles and the voices of the prophets. This net, then, caught all kinds — barbarians, Greeks, Jews, harlots, publicans, and thieves. When it has been filled, that is, when the world has ended, then those in the net are separated. And though we may have believed, if we are found to have become corrupt, we are thrown out. But those who are not, are placed into vessels which are, in fact, the places of eternal dwelling. Every deed, be it good or evil, is called the food of the soul. And the soul, too, has teeth, but they are spiritual in nature. Then the corrupted soul will gnash its teeth, that is, grind together its now impotent faculties of action, because it practiced such things.