Matthew 13:31

(Verse 31.) He proposed another parable to them, saying: The Lord was sitting in a boat, and the crowd stood on the shore: those far away, the disciples closer, could hear. He presents them with another parable, about a rich head of the household who invited guests and provided them with various foods according to the nature of their appetite. Therefore, in the previous parable, He did not say 'another' but 'another one'. For if He had said 'another', we could not expect a third; instead, He said 'another one', so that more would follow.

(Verse 32) The kingdom of heaven is like a mustard seed, which a man took and sowed in his field. It is the smallest of all seeds, but when it has grown, it is greater than the herbs and becomes a tree, so that the birds of the air come and nest in its branches. It should not be a burden to the reader if we present all the parables. For those things that are obscure should be explained more fully, lest they be more entangled by excessive brevity than expounded. The kingdom of heaven is the preaching of the Gospel, and the knowledge of the Scriptures which leads to life; and of which it is said to the Jews: The kingdom of God will be taken away from you, and given to a nation producing its fruits (Matthew 21:43). Therefore, the kingdom of heaven is like a grain of mustard seed, which a man took and sowed in his field. The man who sows in his field is understood by many as the Savior, who sows in the hearts of believers. By others, the man himself who sows in his field, that is, in himself and in his own heart. Who is this who sows, if not our understanding and our soul, who, receiving the grain of preaching, and nurturing the seed with the moisture of faith, causes it to sprout in the field of his own heart? The preaching of the Gospel is the least of all disciplines. Indeed, for the first doctrine has no faith in the truth, preaching man as God, God as dead, and the scandal of the cross. Compare such doctrine with the dogmas of philosophers and their books, the splendor of eloquence and the composition of speeches, and you will see how much smaller it is than the other seeds of the Gospel. But when it grows, it demonstrates nothing biting, nothing vivid, nothing vital, but all flabby and withered, and soft, it boils in vegetables, and in herbs, which quickly wither and fall. […]

The kingdom of heaven is the preaching of the Gospel, and the knowledge of the Scriptures which leads to life, concerning which it is said to the Jews, The kingdom of God shall be taken from you. (Mat. 21:43.) It is the kingdom of heaven thus understood which is likened to a grain of mustard seed. The man who sows is by most understood to be the Saviour, who sows the seed in the minds of believers; by others the man himself, who sows in his field, that is, in his own heart. Who indeed is he that soweth, but our own mind and understanding, which receiving the grain of preaching, and nurturing it by the dew of faith, makes it to spring up in the field of our own breast? Which is the least of all seeds. The Gospel preaching is the least of all the systems of the schools; at first view it has not even the appearance of truth, announcing a man as God, God put to death, and proclaiming the offence of the cross. Compare this teaching with the dogmas of the Philosophers, with their books, the splendour of their eloquence, the polish of their style, and you will see how the seed of the Gospel is the least of all seeds. For the dogmas of Philosophers when they have grown up, show nothing of life or strength, but watery and insipid they grow into grasses and other greens, which quickly dry up and wither away. Brit the Gospel preaching; though it seem small in its beginning, when sown in the mind of the hearer, or upon the world, comes up not a garden herb, but a tree, so that the birds of the air (which we must suppose to be either the souls of believers or the Powers of God set free from slavery) come and abide in its branches. The branches of the Gospel tree which have grown of the grain of mustard seed, I suppose to signify the various dogmas in which each of the birds (as explained above) takes his rest. […]

"Another parable put He forth unto them, saying, The Kingdom of Heaven is like to a grain of mustard seed." That is, since He had said, that of the crop three parts are lost, and but one saved, and in the very part again which is saved so great damage ensues; lest they should say, "And who, and how many will be the faithful?" this fear again He removes, by the parable of the mustard seed leading them on to belief, and signifying that in any case the gospel shall be spread abroad. Therefore He brought forward the similitude of this herb, which has a very strong resemblance to the subject in hand; "Which indeed is the least," He saith, "of all seeds, but when it is grown, it is the greatest among herbs, and becometh a tree, so that the birds of the air come and lodge in the branches thereof." Thus He meant to set forth the most decisive sign of its greatness. "Even so then shall it be with respect to the gospel too," saith He. Yea, for His disciples were weakest of all, and least of all; but nevertheless, because of the great power that was in them, it hath been unfolded in every part of the world.

The grain of mustard seed is both the preaching and the apostles. For though they appeared to be few, they encompassed the whole earth, with the result that the birds of the air, that is, those with frivolous and feathery knowledge of the things above, …

(Mor. xix. 1.) Christ Himself is the grain of mustard seed, who, planted in the garden of the sepulchre, grew up a great tree; He was a grain of seed when He died, and a tree when He rose again; a grain of seed in the humiliation of the flesh, a tree in the power of His majesty. (ubi sup.) The birds lodge in its branches, when holy souls that raise themselves aloft from thoughts of earth on the wings of the virtues, breathe again from the troubles of this life in their words and comfortings.

And it should be noted that, when He says, Sowed good seed, He intends that good will which is in the elect; when He adds, An enemy came, He intimates that watch should be kept against him; when as the tares grow up, He suffers it patiently, saying, An enemy hath done this, He recommends to us patience; when He says, Lest haply in gathering the tares, &c. He sets us an example of discretion; when He says, Suffer both to grow together till the harvest, He teaches us long-suffering; and, lastly, He inculcates justice, when He says, Bind them into bundles to burn.

Through two parables he shows the progress of the evangelical teaching. But because someone might say: if it is so, that it is impeded in such a way that some seed falls by the wayside, some on rocky ground, etc., it seems that it cannot …

He proposed to them another parable - The former parables relate chiefly to unfruitful hearers; these that follow, to those who bear good fruit. The kingdom of heaven - Both the Gospel dispensation, and the inward kingdom.

Another parable put he forth unto them, saying,....

The parable of the wheat and tares, which occupies the chief part of these verses, is one of peculiar importance in the present day. It is eminently calculated to correct the extravagant expectations in which many Christians indulge as to the effect of missions abroad, and of preaching the Gospel at home. May we give it the attention which it deserves! In the first place, this parable teaches us that good and evil will always be found together in the professing church, until the end of the world.

The parable of the wheat and tares, which occupies the chief part of these verses, is one of peculiar importance in the present day. It is eminently calculated to correct the extravagant expectations in which many Christians indulge as to the effect of missions abroad, and of preaching the Gospel at home. May we give it the attention which it deserves! In the first place, this parable teaches us that good and evil will always be found together in the professing church, until the end of the world. The visible church is set before us as a mixed body: it is a vast “field” in which “wheat” and “tares” grow side by side. We must expect to find believers and unbelievers, converted and unconverted, “the children of the kingdom” and “the children of the wicked one”all mingled together in every congregation of baptized people. The purest preaching of the Gospel will not prevent this. In every age of the church the same state of things has existed: it was the experience of the early Fathers; it was the experience of the Reformers; it is the experience of the best ministers at the present hour. There has never been a visible church or a religious assembly of which the members have all been “wheat.” The devil, that great enemy of souls, has always taken care to sow “tares.” The most strict and prudent discipline will not prevent this: Episcopalians, Presbyterians and Independents all alike find it to be so. Do what we will to purify a church, we shall never succeed in obtaining a perfectly pure communion: tares will be found among the wheat; hypocrites and deceivers will creep in; and worst of all, if we are extreme in our efforts to obtain purity we do more harm than good: we run the risk of encouraging many a Judas Iscariot, and breaking many a bruised reed. In our zeal to gather up the tares, we are in danger of rooting up the wheat with them.

The kingdom of heaven is like to a grain of mustard seed - This parable is a representation of the progress of the Gospel in the world; and of the growth of grace in the soul. That grace which leads the soul to the fullness of glory may begin, and often does, in a single good desire - a wish to escape hell, or a desire to enjoy God in heaven.

This especially is true of the toy theatre; that, by reducing the scale of events it can introduce much larger events. Because it is small it could easily represent the earthquake in Jamaica. Because it is small it could easily represent the Day of Judgment. …