The Saducees, another group opposing Jesus, also failed in their tactic of asking a trick question.
When the Pharisees heard that Jesus had silenced the Saducees, they decided to make yet another attempt. They addressed him as "Teacher," (were they being sarcastic? surely, they didn't think Jesus could teach them anything?) They asked him "Which commandment of the law is most important?"
Were they trying to get him to say that some of the law was less important than the others? Do we believe that? What distinctions do we make? What the difference between naming what's most important and summarizing the law? When prophets summarized the law (see Micah 6:8; Isaiah 33:15-16; 56:1; Amos 5:14-15), were they saying that the rest of the instruction is unimportant?
Jesus responds to them by quoting scripture (Deuteronomy 6:5 and Leviticus 19:18). Is he saying the rest of the instruction is unimportant? Or, is he saying all the instructions that the Scripture gives us is intended to help us do these things: Love God and love neighbor?