Thematic Bible: A mustard seed

He set forth to them another parable, saying. "The kingdom of heaven is like a mustard-seed which a man took and planted in his field. "This is indeed the smallest of seeds, but when it is grown it is greater than any herb, and becomes a tree, so that the winged things of the sky come and roost in its branches."

"To what shall we compare the kingdom of God?" he said again. "in what parable shall we set it forth? It is like a mustard-seed, which, when sown in the soil, is the smallest seed in the world; yet when sown shoots up and becomes larger than any plant, sending out such branches that the wild birds build their nests under its shadow." read more.
With many such illustrations Jesus used to tell his message to people as far as they were able to receive it;

This led him to say. "What is the kingdom of God like? And to what shall I compare it? "It is like a grain of mustard seed, which a man took and cast into his own garden. It grew and became a tree, and the wild birds nested in its branches."