Mustard

The mustard seed appears in the Gospels as a small object used to picture two different things: the kingdom of God, which begins minutely and grows to great size, and faith, where even a grain-sized measure has disproportionate effect. The image surfaces in three sayings of Jesus across Mark and Luke.

The Kingdom Parable

In Mark, the parable answers a question Jesus poses about how to picture the kingdom: "And he said, How shall we liken the kingdom of God? Or in what parable shall we set it forth?" (Mr 4:30). The seed itself is named for its smallness: "It is like a grain of mustard seed, which, when it is sown on the earth, though it is less than all the seeds that are on the earth," (Mr 4:31). The contrast comes in the next verse, where the smallest seed produces the largest garden plant: "yet when it is sown, grows up, and becomes greater than all the herbs, and puts out great branches; so that the birds of the heaven can lodge under its shadow" (Mr 4:32).

Luke gives the same parable in similar terms, again opening with a framing question: "He said therefore, To what is the kingdom of God like? And to what shall I liken it?" (Lu 13:18). His version places the planting in a garden and ends with the seed becoming a tree: "It is like a grain of mustard seed, which a man took, and cast into his own garden; and it grew, and became a tree; and the birds of the heaven lodged in its branches" (Lu 13:19). Both Gospels close with the same image of birds nesting in the branches of the grown plant.

The Saying on Faith

The mustard seed serves a second purpose in Luke 17 as a measure of faith. When the apostles ask the Lord to increase their faith, his answer turns on the same image of smallness: "And the Lord said, If you⁺ had faith as a grain of mustard seed, you⁺ would say to this sycamine tree, Be rooted up, and be planted in the sea; and it would obey you⁺" (Lu 17:6). The point is no longer growth from small to great; it is that even faith of mustard-seed scale carries power over a sycamine tree.