Cross reference
Matthew 13:10
10 The disciples came, and said to him, "Why do you speak to them in parables?"
Mark 4:33-34
33 With many such parables he spoke the word to them, as they were able to hear it.
34 Without a parable he didn't speak to them; but privately to his own disciples he explained all things.
Mark 4:10
10 When he was alone, those who were around him with the twelve asked him about the parables.