Mark 4:13
Then Jesus said to them, don't you understand this parable? How then will you understand any parable? — the question is not a rebuke of the disciples' ignorance but a communication of the sower parable's foundational status. This parable is the key to the others: if you understand how the kingdom works in the sower parable (the word goes out, different soils respond differently, abundant harvest results), you have the hermeneutical key for every other parable. The question how then will you understand any parable is not despair but instruction: understand this one, and the others become intelligible.