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Yishai Kiel





How the Concept of Mosaic Authorship Developed



APA e-journal

Yishai Kiel





How the Concept of Mosaic Authorship Developed






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How the Concept of Mosaic Authorship Developed

In the Persian period, the Torah, which is made up of various law collections, was ascribed to Moses as revealed by YHWH. A parallel development was taking place in Achaemenid Persia that sheds light on this process: The sacred texts called the Avesta, that contain the law​​ (dāta) and tradition (daēnā) of Zoroastrianism​, were being collectively ascribed to Zarathustra (Zoroaster) as revealed by Ahuramazdā.


How the Concept of Mosaic Authorship Developed

Zarathustra, the Persian prophet. By Nicholas Roerich 1931  State Museum of Oriental Art, Moscow, Russia. Wikiart

The Pentateuch never claims divine origin or Mosaic authorship.[1] While exactly how this became the authoritative view in rabbinic Judaism and early Christianity is uncertain, some evidence regarding this process can be gleaned from the semantic unfolding of the term torah in the Bible.

The Semantic Development of the Term Torah

The term torah means “teaching” or “instruction.” Often, it refers to a specific instruction, such as the decisions given by a judge (Exod 18:16; Deut 17:11) or the instructions given by God to Abraham (Gen 26:5). In P, the term torah generally refers to a body of instructions pertaining to a certain ritual or rite. This usage of torah is likely rooted in a reality of priestly ritual instructions recorded in short scrolls, each carrying a specific body of instructions pertaining to a particular topic and marked by a colophon.

D, in contrast, applies the term torah more broadly, encompassing a “code” or collection of laws. The term there refers specifically to the legal part of Deuteronomy (some form of chs. 12-26), which is said to have been delivered by Moses to the Israelites on the plains of Moab. It is in this context that the term torah reflects a more central religious conception and comes to refer to what ultimately becomes a canonical composition.

It is mainly in Deuteronomy that the term torah is applied to a written document in particular, as reflected in the frequent use of the phrases ספר התורה (“the book of the torah”) and ספר הברית (“the book of the covenant”) as well as various instructions relating to writing.[2]

The Deuteronomistic History sometimes uses phrases such as תורת משה (“the torah of Moses”), ספר תורת משה (“the book of the torah of Moses”), and ספר התורה (“the book of the torah”) to refer not merely to the laws of Deuteronomy 12-26, but to the entire literary book of Deuteronomy, including its historical and rhetorical introductions.[3] For example, Joshua 8:31 describes the building of the altar on Mount ʽEbal as follows: “as Moses, the servant of YHWH, had commanded the Israelites, as is written in the book of the torah of Moses (בספר תורת משה),” a reference to Deuteronomy 27:2-8.

“The Torah of Moses” in Postexilic Biblical Books

In the postexilic works (mainly in Ezra-Nehemiah and Chronicles), the term torah assumes a broader semantic range encompassing most, if not all, of the Pentateuch as it alludes to laws found, at the very least, in the Deuteronomic and Priestly law collections (including the Holiness legislation). Thus, when referring to תורת משה, “the Torah of Moses,” these works are envisioning what we call the Pentateuch, or at least a relatively mature version of it.[4]

The implications of this semantic shift are far-reaching: this innovative conceptualization of torah contributes to the perception of the textual unity of the Pentateuch as revealed legislation. The figure of Moses to whom the torah is emphatically ascribed is likewise transformed in this framework, in the sense that Moses is no longer the mediator of a single law code, but also the personal authority justifying the authorial fusion of distinct Pentateuchal codes into a textual and legal unity.[5]

The authors of Ezra-Nehemiah projected the consolidation of the torah onto the figure of Moses, with Ezra as the mediating official chosen by both the Persian king and YHWH to bring this Torah to Judea and ensure its central position among the Jews:

עזרא ז:ו הוּא עֶזְרָא עָלָה מִבָּבֶל וְהוּא סֹפֵר מָהִיר בְּתוֹרַת מֹשֶׁה אֲשֶׁר נָתַן יְ-הוָה אֱלֹהֵי יִשְׂרָאֵל וַיִּתֶּן לוֹ הַמֶּלֶךְ כְּיַד יְ-הוָה אֱלֹהָיו עָלָיו כֹּל בַּקָּשָׁתוֹ.
Ezra 7:6 that Ezra came up from Babylon, a scribe expert in the Torah of Moses which YHWH God of Israel had given, whose request the king had granted in its entirety, thanks to the benevolence of YHWH toward him.

A central conception of Ezra-Nehemiah is that YHWH gave His laws as the written Torah to Moses, and Ezra’s job was to promulgate this Torah, ensuring that it is fulfilled by the Jews.

YHWH’s Torah and Ahura-Mazda’s Dāta

A similar conception is found in Zoroastrian thinking during this period. The law (dāta) is set down by Ahura Mazdā,[6] the supreme deity in Zoroastrianism. In fact, the book of Ezra explicitly makes this parallel by having King Artaxerxes I (r. 465–424 BC) use the Persian word as a synonym for Torah in his proclamation appointing Ezra as leader:

עזרא ז:כה וְאַנְתְּ עֶזְרָא כְּחָכְמַת אֱלָהָךְ דִּי בִידָךְ מֶנִּי שָׁפְטִין וְדַיָּנִין דִּי לֶהֱו‍ֹן דאנין [דָּאיְנִין] לְכָל עַמָּה דִּי בַּעֲבַר נַהֲרָה לְכָל יָדְעֵי דָּתֵי אֱלָהָךְ וְדִי לָא יָדַע תְּהוֹדְעוּן. ז:כו וְכָל דִּי לָא לֶהֱוֵא עָבֵד דָּתָא דִי אֱלָהָךְ וְדָתָא דִּי מַלְכָּא אָסְפַּרְנָא דִּינָה לֶהֱוֵא מִתְעֲבֵד מִנֵּהּ הֵן לְמוֹת הֵן לשרשו [לִשְׁרֹשִׁי] הֵן לַעֲנָשׁ נִכְסִין וְלֶאֱסוּרִין.
Ezra 7:25 And you, Ezra, by the divine wisdom you possess, appoint magistrates and judges to judge all the people in the province of Beyond the River who know the laws of your God, and to teach those who do not know them. 7:26 Let anyone who does not obey the law of your God and the law of the king be punished with dispatch, whether by death, corporal punishment, confiscation of possessions, or imprisonment.[7]

While the term דת\דתא is attested elsewhere in the Bible in a more general sense of “law, custom,”[8] Ezra 7:26 is using it as a reference to Torah, i.e., God’s laws. This reflects the term’s usage in the Avesta (the collection of the Zoroastrian sacred texts), which commonly uses dāta to designate divinely revealed law.

While there is no consensus regarding the date of the Avesta, many scholars believe that Avestan works crystalized orally between the late second and early first millennium B.C.E, before the advent of the Achaemenids—in other words before the period of Ezra and Nehemiah.

The Law of Ahura Mazdā as Revealed to Zarathustra

A number of phrases found in the Young Avesta[9] solidify the connection between the law set by Ahura Mazdā and the revelation to Zarathustra.

The Dāta of Zarathustra – The Avesta contains a parallel phrase to Ezra’s “Torah of Moses,” namely, “the law of Zarathustra” (dāta zaraθuštri),[10] which seems to designate a manifestation of the Zoroastrian Tradition. The personal attribution to the “prophet” Zarathustra, as the authoritative recipient and mediator of the law set down by Ahura Mazdā, serves to unify the various components of the religious tradition and justify their inclusion in a single coherent notion of textual unity and scriptural revelation.

The Daēnā[11] of Ahura Mazdā and Zarathustra – In Young Avestan passages, daēnā refers, among other things, to the totality of traditions and instructions revealed by Ahura Mazdā to Zarathustra (Videvdad 2.1-2):[12]

Zarathustra asked Ahura Mazdā: “O Ahura Mazdā, most Life-giving Spirit, Orderly creator of all things in the world of the living with bones, with whom among men did you first converse, you, Ahura Mazdā, other than me, Zarathustra? To whom did you exhibit the daēnā, the one of Ahura Mazdā and Zarathustra?[13]

“Taught by Ahura Mazdā, spoken by Zarathustra” (mazdō.frasāsta zaraθuštrō.fraoxta) – This expression appears in a number of Young Avestan passages.

Beyond All Other Words – In another Young Avestan text (Videvdad 5.23), the “law of Zarathustra” is praised as being above and beyond all other “words,” presumably due to its divine origin:

Then Ahura Mazdā said: “Well, Spitama Zarathustra, it is like this, this law (dātəm), the one discarding the old gods (vīdōiiūm), in the Tradition of Zarathustra, (is) above and beyond other words in greatness, goodness, and beauty, like the Vourukasha Sea is above and beyond other waters.”

The Avesta is the law of Zarathustra – A later Pahlavi (Middle Persian) gloss, from the Sasanian period or perhaps earlier, but which is probably based on the earlier evidence surveyed, explicitly identifies the “law of Zarathustra” and the “sacred word” with the Avesta.[14]

In sum, the dāta and daēnā of Zarathustra were linked to the Avesta, as representing the totality of the Zoroastrian Tradition as revealed to Zarathustra by Ahura Mazdā.

Moses and Zarathustra

The Avestan construction of the “law of Zarathustra” subsumes under its wings a variety of sacred utterances and manifestations of divine revelation. The personal authority of Zarathustra, as the recipient and mediator of the law set down by Ahura Mazdā, serves to unify and consolidate the various components of the Zoroastrian Tradition as well as justify their inclusion in a single coherent framework of textual unity and scriptural authority.

Similarly, Moses functions in Ezra-Nehemiah not merely as a mediator of a single law code revealed by God (as in the pre-exilic and exilic accounts), but as the scarlet thread unifying and consolidating the various law codes of the Pentateuch. In addition to Ezra 7:6 quoted above, this formulation appears in a number of passages in Ezra-Nehemiah, such as Nehemiah 8:1 and 10:30:

נחמיה ח:א …וַיֹּאמְרוּ לְעֶזְרָא הַסֹּפֵר לְהָבִיא אֶת סֵפֶר תּוֹרַת מֹשֶׁה אֲשֶׁר צִוָּה יְ-הוָה אֶת יִשְׂרָאֵל.
Neh 8:1 … and they asked Ezra the scribe to bring the scroll of the Teaching of Moses with which YHWH had charged Israel.
נחמיה י:ל …וּבָאִים בְּאָלָה וּבִשְׁבוּעָה לָלֶכֶת בְּתוֹרַת הָאֱלֹהִים אֲשֶׁר נִתְּנָה בְּיַד מֹשֶׁה עֶבֶד הָאֱלֹהִים וְלִשְׁמוֹר וְלַעֲשׂוֹת אֶת כָּל מִצְו‍ֹת יְ-הוָה אֲדֹנֵינוּ וּמִשְׁפָּטָיו וְחֻקָּיו.
Neh 10:30 …and take an oath with sanctions to follow the Teaching of God, given through Moses the servant of God, and to observe carefully all the commandments of YHWH our Lord, His rules and laws.[15]

In fact, it is this novel and inclusive construal of Mosaic Torah that serves to justify the weaving of discrete law codes into a single unity, an undertaking inherent in the Pentateuch and reflected in Ezra-Nehemiah’s quotations from the torah.

The related concepts of “the Torah of YHWH through Moses” and “the dāta and daēnā of Ahura Mazdā through Zarathustra” allowed each culture to construct an unprecedented comprehensive scriptural unity by the weaving of discrete elements known through divine revelation, thus creating the Jewish Torah and the Zoroastrian Avesta. Part of giving these projects’ authority was projecting these undertakings back onto the authoritative and authorial figures of Moses and Zarathustra. This seems to have occurred in both cultures at roughly the same time, namely the Achaemenid Period.

Xerxes Invokes the Dāta which Ahuramazdā Set Down

In the Achaemenid period, well after the Avesta consolidated orally, Xerxes I (r. 486-465 B.C.E.) mentions the “law set down by Ahuramazdā” in one of his inscriptions (XPh 46-56):[16]

The man who behaves according to the law (dāta)[17] which Ahuramazdā set down and sacrifices to Ahuramazdā according to the Order (rtāvā) up on high, he will both be blessed while alive and one with Order when dead.[18]

Xerxes’ allusion to “the law set down by Ahuramazdā” is likely referring to the “law of Zarathustra” revealed and taught by Ahura Mazdā according to the Avestan Tradition.[19] This differs from the standard ANE concept of law legislated by the king and authorized by a god, as we see, for example, in the preamble to Hammurabi’s Laws. The textual and scriptural unity of the Avesta understood collectively as the “law set down by Ahura Mazdā” was thus a crucial part of the Achaemenid religious worldview.

The King as an Instantiation of Zarathustra

Scholars have noted that the religious responsibilities of the Achaemenid kings according to the Old Persian inscriptions are directly parallel to those of Zarathustra according to the Avesta, namely to sacrifice to Ahura Mazdā and to preserve the cosmic and political Order. This parallel has led several scholars to speculate, correctly to my mind, that the king in the royal inscriptions consciously embodies or represents Zarathustra, who himself is absent from the Old Persian inscriptions.[20]

Like Zarathustra, the king also became the promoter of the dāta of Ahura Mazdā. When Xerxes urges his subjects to obey “the law set down by Ahura Mazdā,” he is likely very consciously assuming the role of Zarathustra as promulgator of God’s law.

Ezra as Moses

Ezra similarly embodies the role of Moses, granting authority to his textual and legal mission. The Talmud seems to notice how Ezra takes on the mantel of Moses (b. Sanhedrin 21b):

רבי יוסי אומר: ראוי היה עזרא שתינתן תורה על ידו לישראל, אילמלא (לא) קדמו משה.
R. Yossi says: “Ezra was fit to have the Torah given to Israel by him, if it weren’t for the fact that Moses came before him.”[21]

The literary configuration of Ezra’s mission according to Ezra-Nehemiah in terms of the consolidation and promulgation of the Mosaic Torah is informed by the rhetoric that governs the king’s self-perception as promoter of the “law set down by Ahuramazdā.”[22]

It is likely that the Avestan rhetoric of the law of Ahura Mazdā mediated through the figure of Zarathustra reached the Judean scribes via the royal ideology of the Achaemenids. This is supported by the description, noted above, of torah in Ezra 7:26 in terms of divine dāta. This particular link suggests that the authors of Ezra-Nehemiah consciously engaged and responded to contemporary Iranian and Persian notions of revelation, codification, and promulgation of divine law.

I am not suggesting that the Achaemenid authorities played an active role in consolidating Pentateuchal law, as suggested by the theory of royal authorization of the Pentateuch,[23] though this possibility cannot be altogether excluded. Rather, quite naturally, the authors of Ezra-Nehemiah sought to portray the Mosaic authority of Ezra’s mission in the image and likeness of contemporary Persian rhetoric and its subversion of Zarathustra.


May 17, 2018


Last Updated

September 12, 2021


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Dr. Yishai Kiel is a Blaustein postdoctoral associate and lecturer at the Program in Judaic Studies and the Department of Religious Studies at Yale University. He  received his Ph.D. in Rabbinic Literature and Sassanian Studies from the Hebrew University and his rabbinic ordination from the Chief Rabbinate of Israel. He is the author of Sexuality in the Babylonian Talmud: Christian and Sasanian Contexts in Late Antiquity.