Matthew 13:10
And the disciples, having come near, said to Him, "Wherefore dost Thou speak to them in parables?"
Mark 4:10
And, when He was alone, those who were about Him with the twelve asked Him as to the parables.
Mark 4:33-34
And with many such parables He spake the word to them, as they were able to hear it.
Treasury of Scripture Knowledge
Summary
And the disciples came, and said unto him, Why speakest thou unto them in parables?