From The Gospel of Matthew, by Curtis Mitch and Edward Sri, commenting on Matthew 13:1-23
While Jesus occasionally spoke in parables before, here he suddenly addresses the crowds “at length” in parables, giving several in rapid-fire succession. This movement from teaching the crowds primarily in a straightforward manner (Matt 5–7) to a new emphasis on parables (Matt 13) surprises Jesus’ own disciples, who ask, “Why do you speak to them in parables?” (13:10).
For the ancient Jews, a parable was a cryptic saying or story intended to stimulate thought. Parables were sometimes used to communicate God’s judgment on corrupt Israelites for their sins (see 2 Sam 12:1–10; Isa 5:1–7; Ezek 17:2–21; 19:2–19). As we will see, Jesus’ parables in Matt 13 address the indifference of many in Israel to his ministry (Matt 11) and the opposition of the Pharisees who are plotting his death (Matt 12).
When asked about the purpose of his parables, Jesus tells the disciples that knowledge of the mysteries of the kingdom of heaven has been granted to you, but it will not be given to those who do not follow him. Those who have been open to Christ’s teachings will perceive even more: To anyone who has, more will be given. But those with closed hearts will be unable to penetrate the mysteries of the kingdom: from anyone who has not, even what he has will be taken away.
In the punch line (v. 13) Jesus sums up the reason he now teaches in parables. Many in Israel refuse to receive his message: they look but do not see and hear but do not listen or understand. In a fulfillment quotation Jesus points to Isa 6:9–10, a text that tells how the prophet is sent by God to call the people to repentance but predicts that few will take the message to heart.