The mustard seed: Sermon on the penultimate Sunday of the year

By a Dominican Friar   |   13 November 2024

“I shall open my mouth in parables, and make known things hidden from the beginning of the world.”

At the beginning of the world, after our first parents fell into sin, God made a prophecy about a man and a woman. He said that this man and woman would be the enemies of the serpent, and that they would crush the serpent’s head. This prophecy, by which God announced in advance what He would accomplish in the fullness of time, was one of the things which He hid at the beginning of the world. This prophecy was hidden, both in the sense that it was not explained at that time in a clear manner, with all the details about how salvation would occur, but also in the sense that it was put into a secure place; for our first parents treasured the prophecy in their memories, and so also did those of their descendants who were faithful. When He came in the fullness of time, our Lord made this hidden thing known. Yet in speaking to the crowds, He made it known in parables, so that it would not be understood too clearly by those who would not believe, and who would then be more guilty, the more they had understood. Christ tells two parables about the salvation that was promised at the beginning of the world: one parable about the man and the other about the woman. Together these parables explain how our salvation will take place.

In the first, the man sows the mustard seed in the ground. Our Lord will soon tell the disciples that the one who sows the good seed in the parable of the wheat and the tares is the Son of man, that is, Himself, and so we should understand the same to be true here. He is the sower of the mustard seed. As for the mustard seed itself, although it allows of various interpretations, we may understand this, as do some of the Fathers, as being also a reference to Christ. It should not be surprising if Christ is both the sower and the seed, since it is obvious that one image by itself could never be adequate to represent His life. 

Why is a mustard seed a good image of our Lord? Some of the Fathers of the Church make a bold comparison, and say that just as a mustard seed must be pounded and bruised to give forth its fiery flavour, so Jesus by His Passion gave the Holy Ghost to His disciples. But the more immediate sense of the image, as it appears in the gospel, lies the contrast between the apparent unimportance of the seed and the greatness of the tree that grows from it. Our Lord, during His earthly life, was apparently unimportant: He did not have money at His disposal or people at His command, since He desired no followers except for those would come to Him and stay with Him freely. Most assuredly must Christ have seemed unimportant to the high priests and the Herodians when they saw or heard how He had been stripped of His garments and scourged by a group of common soldiers. Yet the image of the mustard seed does not refer only to the outward events and circumstances of our Lord’s life, but also suggests a truth about His inward state. Christ was like a mustard seed in that He was humble. He possessed the virtue of humility in its supreme form, since He saw that His human nature was in itself nothing, and that nevertheless His human nature was and is elevated above all created things by its hypostatic union with the Word. It was in this humility, as St Paul says, that Jesus submitted to death, and to be placed like a mustard seed in the ground.

But if He is compared to a seed in His human life and death, why is He compared to a tree in His Resurrection? For “the mustard seed is smaller than all the seeds”, as the humility of Christ exceeds all humility, “but when it has grown it is greater than all the shrubs”. I think this is a reference not only to the glory of His Resurrection, but also to the fact that, by rising again, He has become the head and principle of the Church. “The Spirit was not yet given,” says St John, speaking of the time before Christ’s death. This does not mean that the Holy Spirit was not yet dwelling in the soul of anyone on earth, since there were already people on earth in a state of grace, and the three divine Persons dwell in the soul of anyone in that state.  But the Holy Spirit was not yet given as He would be on Pentecost, when He first became the soul of the Church. Before Christ’s Passion, there were individuals in a state of grace, but the Mystical Body was not yet in existence. Christ was not yet the Head of His Body, the Church. The mustard seed had not yet become a tree.

Now, what we have said of the Passion, we can say also of the sacrament of the Passion. The mustard seed is something which appears unimportant to human sight.  But in the Holy Eucharist, which is the sacrament of His Passion, what do we have? To human sight, only a little bread and a little wine. Christ clothes Himself in these humble appearances, to be buried again like a mustard seed in the hearts and bodies of believers. But as the Church was founded by His Resurrection, so by Holy Communions this same Church grows, and has become stronger than the kingdoms of the earth.

This, then, is the teaching, or part of the teaching of the first parable. The man who was promised at the beginning of time, and who is also God, by His death and rising has set up the Church in which we can be saved, and the sacraments by which we can be saved. Surely there is no need of anything else? Yet, our Lord now tells us about a woman, the woman who also was promised from the beginning. “The kingdom of heaven is like to yeast which a woman took and hid in three measures of flour, until all was leavened.” I see this as a reference to the Blessed Virgin. How does she co-operate in our salvation? As we know, to be saved, it is not enough just to be in the Church and to receive the sacraments, since St Paul says that people can “eat and drink judgement upon themselves”. We must receive the sacraments well, and faithfully perform our duties of state, and for all this we are in need of actual graces. Hence, when we speak of our Lady as Mediatrix of all graces, we mean at least this: that she obtains for us all the actual graces which we need.

Hence the image of leaven. An actual grace means that the Holy Spirit, the Life-Giver, is moving us to do something supernaturally; leaven is that which makes the flour seem to become alive. The Holy Spirit unites those in whom He works; the leaven unites the flour into a single loaf. We Christians are the flour, who, whether on earth or in purgatory or in heaven, are to be united and to become Christ, the Bread of Life.  And the Blessed Virgin mixes the leaven into this flour, since she, by her compassion on earth and her prayer in heaven, gains all the graces by which the leavening of the Holy Ghost is accomplished.