Jesus gives a parable about a sower to a group of people, but only the disciples can understand what it means. Jesus talks to people in parables because it explained divine truths. They come to the conclusion that people will hear but not understand and see but never perceive. It is a prophecy that Jesus speaks to the people in parables.
The significance of this chapter is to trust the words of God even if you don't understand what he is trying to tell you. Always have faith in God whether you agree or disagree with the words he has shared with you and the others around you.
Indeed, in their case the prophecy of Isaiah is fulfilled that says: "'"You will indeed hear but never understand, and you will indeed see but never perceive." - Matthew 13:14