Jesus focused on seeds in the first three parables he taught by the Sea of Galilee in Matthew 13. The final seed parable — after the parables of the sower and of the wheat and the tares — is the parable of the mustard seed. This parable appears in Matthew, Mark and Luke. The simple parable — which is often parsed down to the word — speaks of the early church growing from a small source into a shelter for all people.
Matthew 13: 31-32
31 Another parable put he forth unto them, saying, The kingdom of heaven is like to a grain of mustard seed, which a man took, and sowed in his field: 32 Which indeed is the least of all seeds: but when it is grown, it is the greatest among herbs, and becometh a tree, so that the birds of the air come and lodge in the branches thereof.