Mishneh Torah

Maimonides (Rambam, Rabbi Moshe ben Maimon) spent about ten years in Fustat writing the Mishneh Torah and finished it around 1180. Unlike his other works, he wrote it in clear Mishnaic Hebrew. Its 14 books, which is why it is also called Yad HaChazakah ("the Mighty Hand", since yad has the numerical value 14), cover the whole of Jewish law. That includes laws that had not applied since the Temple was destroyed, such as sacrifices, ritual purity and the Sanhedrin. It opens with the "foundation of foundations", knowing that God exists, and closes with the Laws of Kings and the messianic age.

Maimonides wrote that a reader could study the Written Torah and then his book and know the entire Oral Law. Critics, above all Rabbi Abraham ben David (the Raavad) of Posquières, objected that it gave rulings without sources or dissenting views, and the work became part of the long Maimonidean controversy. Today it is printed with dozens of commentaries and studied daily around the world in the cycle of one to three chapters a day.