The Parable of the Sower and the Mystery of the Kingdom
Jesus teaches a large crowd from a boat and tells of seed falling on four kinds of ground. When the Twelve and others ask privately, he explains that the seed is the word and that the soils portray different responses—immediate rejection, shallow reception, choking by cares and desires, and fruitful endurance. He also quotes Isaiah 6:9–10 when explaining why parables both reveal and expose.
Where this fits in the story: Mark has just shown sharply different responses to Jesus—from disciples gathering around him to leaders calling his work demonic. The parable explains why the same kingdom word can meet such different outcomes.