Harry Whittaker
Studies in the Gospels

81. The Mustard Seed and the Leaven (Matt. 13:31-33; Mark 4:30-32; Luke 13:18-21)*

In Luke’s gospel the best texts carefully link the parable of the mustard seed with what goes before: “He said therefore...” (RV). This context is completely different from that in Matthew. So the reader is left to conclude either that Jesus spoke these two parables together on two different occasions (a thing not unlikely in itself), or that Matthew, according to his usual method, has brought together in chapter 13 a number of parables that were spoken on different occasions.

What Mustard Plant?

There has been no little difficulty in identifying the mustard Jesus referred to. But whichever it might be, there is no mustard seed which makes a tree. A bush, perhaps, in specially favourable circumstances.

The facts supplied by the gospels are these:

It is the least of seeds.
It is sown (i.e. an annual) in garden or field.
It is a herb or pot-plant.
It becomes a tree, with branches, comparable to the tree of Nebuchadnezzar’s dream (Dan. 4:10-12).
Birds nest in it and under its shadow.

The commentators, failing to recognize that in nearly all the parables of Jesus there is an element of the unreal, have juggled marvelously with this simple assemblage of facts in attempts to make them fit one “mustard” or the other, according to taste.

The big probability is that for his own purpose he deliberately varied some of the natural facts in order to make them conform to the spiritual world which is the main concern of his parable. It is very commonly said that Jesus took his parables straight from nature and from everyday life, but the fact is that there is hardly one of his parables which is true to life in every detail.

Mistaken Interpretations

The almost universal interpretation of the parable is that as the seed is tiny, so also the preaching of the gospel had unpretentious beginnings, but as the plant grew to impressive size, so also will be the outcome of the gospel when Christ’s kingdom is in being. Orthodoxy finds this a specially favourite parable because it can be made to teach the gradual but certain growth of the beneficent influence of the church. Yet today this in an interpretation which doesn’t even make first base.

The other view, popular with many who believe in the coming of the Messianic kingdom and see in this parable a dramatic contrast between unimpressive beginnings and glorious ultimate achievement, labours under two difficulties:

An essential element in the parable is the gradual growth from seed to tree. This is not the way in which the kingdom of God will come about. Its advent will be sudden; if not instantaneous, at least bewilderingly rapid.
The special mention of the birds of the air. In another parable set alongside this one, the fowls of the air are given explicit interpretation: “Then cometh the wicked one and catcheth away that which was sown in his heart” (Mt. 13:19). Would Jesus use the same symbol with contradictory meanings? Would Matthew set inconsistencies of this kind side by side with each other? Clearly, an interpretation of the mustard seed which again allows for association with “the wicked one” has special recommendation.

A Prophecy of Apostasy

Here, then, is the clue as to what Jesus was aiming at. His parable, like the parable of the tares, is a prophecy of the perversion of his gospel in later times. The seed, tiny and unimpressive, represents the Lord’s teaching. The growth into a tree with “great branches” represents an abnormal monstrous development not according to the original nature of the seed. This is the apostasy which came by gradual imperceptible growth from the modest simplicity of the early church. The marvelous designed similarity to the tree of Nebuchadnezzar’s dream now has great point: “upon whose branches the fowls of the heaven had their habitation” (Dan. 4:21). Just as the godless nations of the world were gathered in to the empire of Babylon, so also (Jesus foresaw) the corrupt system developing from the seed of his gospel would hold sway as another Babylon over many peoples.

There is now seen to be further significance in the way the parable is introduced: “Unto what is the kingdom like? and whereunto shall I resemble it?” No other parable is begun in this way. But how similar to the expostulation of Isaiah: “To whom then will ye liken God? or what likeness will ye compare unto him?” (40:18), where immediately there is caustic exposure of the way in which the truth about God Himself was corrupted into a graven image fashioned by human hands. So also, declares Jesus, will the truth of his gospel be corrupted into a system of falsehood.

Supporting Details

Another small detail which chimes in with the view just put forward is the form of the repeated Greek expression in Mark 4:31,32: “whenever it may be (or, should happen to be) sown”, as though implying a contingency with some element of uncertainty about it. This is appropriate if spoken with reference to the indeterminate period of the growth of false Christianity. But if with reference to the preaching of the gospel, this was already achieved, to a considerable extent by Jesus himself.

Further, in Luke 13:19 the Greek text has the emphatic reading: “...which a man took, and cast into his own garden”. This suggests not only (what is easy for all to see) that the gospel was first preached to God’s own nation, but also that it was there where the first serious growth of perverted truth took place. The first and greatest errors in Christian teaching — the Judaistic spirit, justification by works-came from the Jewish element in the ecclesias.

The point about the context of the parable in Luke, mentioned earlier, can now be examined afresh. There, immediately preceding this parable is the incident of the healing of the crooked woman in the synagogue. Jesus was angry at the perversion of the true spirit of Moses’ law manifested in the Pharisaic attitude of the ruler of the synagogue. Was he led on to consider how his own teaching would similarly come to be distorted and misrepresented? Or is the reader of Luke’s gospel intended to go a little further back to another parable (13:6-9) about a fruitless fig tree, which was to be cut down if a last careful attempt at improvement brought no result. Perhaps here Jesus was prophesying that the tree would be cut down, and the mustard seed sown in its place, only to come to a different but equally undesirable result.


It may be argued against this approach to the parable that to interpret as a prophecy of apostasy is to ignore the introductory words: “Unto what is the kingdom of God like? and whereunto shall I liken it? It is like unto...” The repetition and rhetorical questions give an impression of Jesus thinking aloud about Isaiah 40:18 and at the same time seeking a parable to meet the situation. How is the interpretation just suggested to be seen as a picture of the kingdom of God?
Quite simply, it is not.

Such a question overlooks the fact that this is the Lord’s usual way of introducing a parable which has reference to some aspect of the kingdom. For example, “Then shall the kingdom of heaven be likened unto ten virgins”. But five of these were foolish and shut out. Again, “the kingdom of heaven is like unto a certain king, which made a marriage for his son”. But in the parable the king is God. It is the marriage which represents a certain aspect of the kingdom. (see also Mt. 18:23; 20:1; 13:45). Failure to recognize the idiom as meaning: “Here is another parable which has to do with the kingdom”, has led many interpreters of the parables into a wrong emphasis.

The point needs to be borne in mind in examination of the parable of the leaven. “The kingdom of heaven is like unto leaven” does not necessarily mean that the leaven here represents either the gospel or the kingdom which the gospel proclaims.

Leaven in Scripture

Indeed either of these conclusions is ruled out in extraordinarily emphatic fashion by a simple consideration of the Bible usage of the word “leaven”. Always this expression has bad associations.

“Beware of the leaven of the Pharisees, which is hyprocrisy” (Lk. 12:1).

“Purge out therefore the old leaven...Therefore let us keep the feast, not with the leaven of malice and wickedness...” (1 Cor. 5:7,8).

“A little leaven leaveneth the whole lump” (Gal. 5:9). Paul meant the leaven of Judaism. He may even have been making direct allusion to the Lord’s parable.

In the O.T. the same Hebrew root means ‘cruel’ (Ps. 71:4). ‘grieved’ (73:21), ‘oppressed’ (ls. 1:17)
The exclusion of leaven from the meal-offering and other forms of sacrifice reinforces this interpretation. The wave-sheaf offered at Passover was, of course, in no way associated with leaven; it represented Christ. But the two wave-loaves offered at Pentecost represented the saints, who are redeemed sinners, and appropriately they were “baken with leaven”.

Examples such as these make it evident that Jesus would no more have dreamed of making a direct comparison of his kingdom to leaven than he would of comparing it to a garbage bin.

Spreading Corruption

The obvious alternative, then, is that the Lord intended his similitude to foretell the inevitable spread of corruption through the church “until the whole was leavened”. Far from seeing the gospel conquer the world, he expected the world to conquer the gospel.

In this the parable is marvellously true to experience. Apostasy, serious and widespread, came into the church whilst the apostles were still alive. This brought about a rapid decay of truth and good Christian living, “until the whole was leavened”. ‘The mystery of iniquity doth already work’ is probably another Pauline allusion to this parable (2 Th. 2:11).

Rather strangely, it has become almost a dogma in some quarters to believe that in every century the Truth has somehow survived in obscure communities in different parts of the world. Acceptance of this idea has been more through inclination than evidence, for certainly there is no indication in the Bible that this would be the case, nor is there historical evidence which by the most easy-going standards would establish a case for continuous survival of ecclesias of faithful believers. Historically everything points the other way. And so also does the parable of the leaven.
he close similarity to the parable of the mustard seed, in general idea, is hinted at in the opening words: “Another parable spake he unto them”. The word means “another of similar character’, not “another of a different sort”.

Those who would interpret with reference to the gradual spread of the gospel or of the kingdom need to bring evidence (a) that the gospel has conquered or will by slow degrees conquer the world; (b) that when it comes the kingdom will be established in slow gradual fashion; do not many Scriptures (e.g. Mal. 4:1-3; Ez. 38:18-23: Rev. 14:7; 15:4 etc., etc.) point to an exactly opposite conclusion?

One Strange Detail

Just as the mustard seed had its noticeable feature which is not true to experience, so also with the leaven. The woman put the leaven into “three measures of meal”. More than seventy pounds of flour means well over a hundredweight of bread. Some family baking!

Then why was Jesus at pains to specify “three measures of meal”? It may be that this was intended to signify the three branches of the human race descended from the sons of Noah. An explanation of a different kind is this: The rabbis laid down that the wave sheaf of barley cut on the day after the Passover sabbath for presentation to the Lord (Lev. 23:10) was to be “three measures” in quantity. The parable would thus appear to represent the truth about the risen Christ becoming completely corrupted.

Another possibility is that Jesus was making deliberate reference to the “three measures of fine meal” prepared by Sarah for her three angelic guests when they came to announce the birth of the promised Seed (Gen. 18:10). In that case the idea is much the same, but there remains the difficulty of quantity. Sarah surely used a different size of “measure”.
Again, why should the woman be said to hide the leaven in the meal? This is hardly the most natural word to use. It seems to suggest an attempt at deliberate quiet corruption of the Truth.

Notes: Mt. 13:31-33

The birds of the air. Other Scriptures support the interpretation of this detail: Gen. 15:11 (human hostility to God’s covenant with Abraham); Ez. 31:6 (the expansion of imperial Assyria); ls. 34:14,15 (unclean birds of judgment).
Leaven was used in the Talmud as a symbol of evil desire.
Three measures comes also in ls. 5:10 LXX, but there it is the yield of a vineyard and not a baking.
The whole was leavened. In the Lk. context this parable is followed appropriately by the enquiry: “Lord, are there few that be saved?” (13:23).

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