Subdividing the Seven Laws
Various rabbinic sources have different positions on the way the seven laws are to be subdivided in categories. Maimonides (Melakhim 10:6 of the Mishneh Torah) lists one additional Noahide commandment forbidding the coupling of different kinds of animals and the mixing of trees. Maimonides commentator Radbaz expressed surprise that he left out castration and sorcery which were listed in the Talmud (Sanhedrin 56b).
The tenth-century rabbi Saadia Gaon added tithes and levirate marriage. The eleventh-century Rav Nissim Gaon included "listening to God's Voice," "knowing God" and "serving God" besides going on to say that all religious acts that can be understood through human reasoning are obligatory upon Jew and Gentile alike. The fourteenth-century rabbi Nissim ben Reuben Gerondi added the commandment of charity.
The sixteenth-century work Asarah Maamarot by Rabbi Menahem Azariah of Fano (Rema mi-Fano) enumerates thirty commandments, listing the latter 23 as extensions of the original seven. Another commentator (Kol Hidushei Maharitz Chayess I, ch. 10) suggests these are not related to the first seven, nor based on scripture, but were passed down by oral tradition. The number 30 derives from the statement of the Talmudic sage Ulla in tractate Hullin 92a, though he lists only three other rules in addition to the original seven, consisting of the prohibitions against homosexuality and cannibalism, as well as the imperative to honor the Torah.
The tenth-century Shmuel ben Hophni Gaon lists thirty Noahide commandments based on Ulla's Talmudic statement, though the text is problematic. He includes the prohibitions against suicide and false oaths, as well as the imperatives related to prayer, sacrifices and honoring one's parents. The commandments, according to Shmuel ben Hophni Gaon, cover:
Prohibition against idolatry
No idolatry to other gods
To pray to Hashem
To offer ritual sacrifices only to Hashem
Prohibition against blasphemy
To believe in the singularity of God (Monotheism)
No blasphemy
No witchcraft
No soothsayers
No conjurers
No sorcerers
No mediums
No demonology
No wizardry
No necromancy
To respect father and mother
Prohibition against murder
No murder
No suicide
No Moloch worship (infant sacrifice)
Prohibition against theft
No stealing
Prohibition against sexual immorality
Formal legal marriages
No adultery
No incest
No sodomy (i.e. homosexuality)
No bestiality
Not to crossbreed animals
No castration
Prohibition against eating the limb of a living animal
Not to eat a limb of a living creature (whilst it is still alive)
Not to eat or drink blood
Not to eat carrion (for those recognized by a Beth Din)
Establish Courts of Justice
To establish courts and a system of justice
No false oaths
The contemporary Rabbi Aaron Lichtenstein counts 66 instructions, but Rabbi Harvey Falk has suggested that much work remains to be done in order to properly identify all of the Noahide commandments, their divisions and subdivisions.
Theft, robbery and stealing covers the appropriate understanding of other persons, their property and their rights. The establishment of courts of justice promotes the value of the responsibility of a corporate society of people to enforce these laws and define these terms. The refusal to engage in unnecessary lust or cruelty demonstrates respect for the creation itself as renewed after the flood. To not murder includes the prohibition against human sacrifice.