Full Idea
What is hateful to you, do not unto your neighbour: this is the entire Torah. All the rest is commentary - go and study it.
Clarification
The Torah is the collection of early Jewish scriptures
Gist of Idea
The Torah just says: do not do to your neighbour what is hateful to you
Source
Hillel the Elder (reports [c.10]), quoted by Paul Johnson - The History of the Jews Pt II
Book Reference
Johnson,Paul: 'A History of the Jews' [Phoenix 1993], p.127
A Reaction
Johnson suggests that this idea, of stripping everything from the Torah except its basic morality, was passed on to Jesus by Hillel. Suppose you hate Arsenal, but your neighbour supports them, and they just won the European Cup? What should you do?