This chapter is a big sack of parables, and we’ve already seen that a parable is in essence a comparison, where light is thrown on something by talking about something else, better known or more clear or vivid. The parable of the the sower is particularly complicated and developed, with lots of details but still turns on a comparison. Though Jesus does not (at first) tell his audience what it is, he wants them to think: “if you have ears then hear!”
There is an English proverb that’s pretty close to Jesus puzzling saying about why he spoke in parables (Matthew 13:10-15). It helps us to understand what is going on and shows us how the Sower is all about grace (not being a more efficient evangelist) but that grace can only work when the soil is ready – you have to want to be saved!
We’ll also notice how Matthew like Luke (maybe they both copied the same Master?) puts parables together so that they help explain each other. I’ll also suggest that talk of a fire that will burn up the dud fish and the tares makes better sense if we are willing to give over the right to judge to God, and not to think we can know the rules God MUST apply. (See Jonah on that 🙂