In Luke 13:20, Jesus follows with the leaven parable—both describe the kingdom's small beginnings and great growth in sequence.

In Matthew 13:31, the same mustard seed parable describes the kingdom growing from a tiny seed into a large tree.

In Mark 4:30-34, the mustard seed parable is recorded with similar details—the kingdom starts small and becomes great.

In Mark 4:31, the same parable begins with the mustard seed as smallest seed — it echoes the question about the kingdom's nature.