Matthew 13:34
Jesus spoke all these things to the crowds with parables. He did not say anything to them without using a parable.
Mark 4:33-34
And He spoke "the word" to them [i.e., the crowds] with as many such parables as they were able to receive.
John 16:25
"I have spoken these things to you in figurative language. [However], the time will come when I will not speak to you in figurative language, but will tell you plainly about the Father.
Matthew 13:13
Therefore, I am speaking to them with parables because [although] they can see, they [really] do not perceive, and [although] they can hear, they [really] do not comprehend, and so they [utterly] fail to understand [what I am trying to get across].