In Rabbinic Judaism, the laws of conversion are based on the classical sources of Jewish law, especially discussions in the Talmud, and the law as codified in the Shulkhan Arukh. This corpus of traditional Jewish law (halakha) is regarded as authoritative by the Orthodox and Conservative movements. The traditional halakhic requirements for conversion are instruction in the commandments, circumcision (if male), and immersion in an acceptable body of water before valid witnesses, and acceptance of the commandments before a rabbinical court. If a male is already circumcised, a drop of blood is drawn from the penis.