The Parables of the Mustard Seed and the Leaven

In Matthew 13:31–33, Jesus tells two parables about the growth of the kingdom of heaven on earth during this age. 

The parable of the mustard seed:

"He put another parable before them, saying, 'The kingdom of heaven is like a grain of mustard seed that a man took and sowed in his field. It is the smallest of all seeds, but when it has grown it is larger than all the garden plants and becomes a tree, so that the birds of the air come and make nests in its branches.'" (13:31-32)

The mustard seed was proverbially small, and yet it grew to tower over all the vegetables, growing to be about 10 feet tall. Jesus describes it as a tree, recalling Old Testament imagery. In Daniel 4:10-12, 20-22 King Nebuchadnezzar and his imperial dominion is described as a great tree in which the birds find shelter. In Ezekiel 17:22-24 God promises to plant the offspring of David as a twig that will become a great tree in which the birds find shelter. Thus Jesus describes the extensive growth of the kingdom of heaven over the earth. The nations will take refuge in it.

The parable of the leaven:

"He told them another parable. 'The kingdom of heaven is like leaven that a woman took and hid in three measures of flour, till it was all leavened.'" (13:33)

The hidden leaven grows to transform every part of the dough. Three measures is a lot of flour, around 60lbs of flour, enough to feed about 150 people, so that Jesus emphasizes the vast and pervasive transformation resulting from what appears to be a little thing. In Matthew 16:5-12, Jesus warned of the "leaven of the Pharisees and the Sadducees," referring to their teaching. So in this parable, he refers to the transforming and contagious impact of his teachings. He describes the intensive growth of the kingdom in the earth, impacting every part. 

From these two parables we learn three things about the kingdom of heaven:

1. The kingdom of heaven begins small and often works in hidden ways. Its weapons are not of the flesh or of the world, but have divine power to destroy strongholds (2 Cor. 10:4). It looks foolish and weak until it puts the wise and powerful to shame. Many of its victories are not public or the kinds of things that make the news. It becomes evident in time, but it continues to work even when its work is not so evident. 

2. The kingdom of heaven grows during this age. It does not come to earth fully formed - not as a tree, but as a seed. It does not win with one decisive battle, but a long campaign in which it progressively gains ground. Its growth might be imperceptible - try watching dough rise or a plant grow - but it is progressive and ongoing. The progress can be seen in the light of history.

3. There is a twofold benefit to this kingdom: it is a shelter and a transforming power. It is a tree where the birds make their nest and it is leaven which transforms the dough. First, it is a shelter where there is reconciliation with God rather than condemnation, favor rather than wrath. In this kingdom there is justification and adoption, and thus peace and joy, through Jesus Christ (Col. 1:12-14). Second, it is a power which sanctifies, turning people from sin unto righteousness. Jesus reigns in our hearts by his grace, producing sanctification, societal reform, and a new way of life. His kingdom is the opposite of sin’s corrupting effect. As a little sin can spread its corrupting influence in people and communities (1 Cor. 5:6), so the reign of Christ spreads is reforming influence in people and communities. 

For more on these two parables and six practical implications of these lessons, listen to my recent sermon: The Parables of the Mustard Seed and the Leaven.