Did you guess Psalms, or did you know it was Deuteronomy?  The latter is a review of Exodus, Leviticus and Numbers, so Jesus quoting it was like referencing the whole Law of Moses, except for Genesis, but He talked about that as well, so don’t feel like it was neglected.  What is the theme of the Old Testament?

-Do right-

-Love everybody-

-Obey God-

-The Messiah is coming-