Another interesting theme of the chapter: in an earlier post about Jonah, I mentioned the Greek concept of people being motivated by the belly (physical desires), heart (feeling for others), and mind (mental desires, mostly money). In the beginning of this chapter, Christ adds another component to this triun of motivation: religion. The Greeks operated from the belly, heart, and mind, but the Jews were also driven by religion.
In this chapter, the belly is represented by Jonah who was in the belly of the fish; the mind is represented by Solomon, and religion is represented by the temple. What does Christ say about each? One greater than the temple is here. One greater than Jonah is here. One greater than Solomon is here. What is greater than religion, the belly, and the mind? The heart, feelings that we have for others. Christ is the one inside the heart of the earth.
Christ doesn't say that there is anything wrong with religion, physical needs, or mental desires. He just says that our feelings for others are the highest desire.
See how subtly this case is made? You only find it if you look closely at the text. How important is it? Feeling for others is THE over-arching theme of the chapter, uh, that is, all the Gospels, but you probably knew that.