Matthew 13:32
Although it is the smallest of all seeds, yet it grows into the largest of garden plants and becomes a tree, so that the birds of the air come and nest in its branches.”
What it says
The seed grows into a large plant that shelters birds.
What it is doing
Unexpected growth fills the image.
In context
31He put before them another parable: “The kingdom of heaven is like a mustard seed that a man took and planted in his field. 32Although it is the smallest of all seeds, yet it grows into the largest of garden plants and becomes a tree, so that the birds of the air come and nest in its branches.”