Kuzari

The Kitab al Khazari, commonly called the Kuzari, is one of the most famous works of the medieval Spanish Jewish philosopher and poet Rabbi Yehuda Halevi, completed around 1140. Its title is an Arabic phrase meaning Book of the Khazars, while the subtitle "The book of refutation and proof on behalf of the most despised religion" shows its purpose and context in medieval Jewish apologetics.