Jesus explains his parables and tells a few more—the farmer sowing, the lamp, the growing seed, the wheat and the weeds, the mustard seed, the yeast, the hidden treasure and the pearl: Matthew 13:10–23; Luke 8:9–18; Mark 4:21–29; Matthew 13:24–30; Mark 4:30–34; Matthew 13:31–52; Mark 4:35–41; Matthew 8:23–27; Luke 8:22–25

In His public speaking, Jesus often, if not always, used parables to teach people about the Kingdom of Heaven.

The disciples asked why: wouldn’t it be easier for everyone if Jesus just said it in plain, everyday language?

^{Matthew 13:12-13} To those who listen to my teaching, more understanding will be given, and they will have an abundance of knowledge. But for those who are not listening, even what little understanding they have will be taken away from them. That is why I use these parables,
For they look, but they don’t really see.
They hear, but they don’t really listen or understand.

Well, no. Speaking plainly to people who would never believe wasn’t going to help them or anyone else.

Jesus said this (and presumably the Pharisees behaved like this) in fulfillment of the prophecy of Isaiah 6:9-10 (as quoted from the Greek scriptures by Mark:

^{>Matthew 13:14-15} When you hear what I say,
you will not understand.
When you see what I do,
you will not comprehend.
For the hearts of these people are hardened,
and their ears cannot hear,
and they have closed their eyes—
so their eyes cannot see,
and their ears cannot hear,
and their hearts cannot understand,
and they cannot turn to me
and let me heal them.’

(It reads slightly differently in modern translations, but the meaning is the same.)

Isaiah initially gave this as a warning to the Northern Kingdom of Israel as they turned their backs on God, and refused to listen to not only Isaiah, but to other prophets—Hear nothing, see nothing, have nothing. Jeremiah gave a similar message to Judah in the lead-up to the fall of Jerusalem. Now Jesus was applying it to His situation: someone bringing God’s word to the people, and being ignored (again).

Jesus was still comparing the religious leaders of the day to those who had faced judgement in previous phases of Israel’s history, but this time, He was doing it quietly, just to the disciples.

Could anyone have asked Jesus the question and got the same answer? I’d have to say yes, on the basis that:

^{Matthew 13:12} To those who listen to my teaching, more understanding will be given, and they will have an abundance of knowledge.

Those who refused to listen and believe—despite the explanations, the healings, driving out of demons, the other miracles—were never going to understand, and were more likely to harden their hearts completely and risk blaspheming the Holy Spirit.