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Rabbi Isaiah HaLevi ben Mishaʾel: The Rambam's Brother-in-Law and His Two Works

Yehuda Seewald

 

Among the lesser-known figures in medieval Jewish scholarship stands Rabbi Isaiah HaLevi ben Mishaʾel. His persona has begun to take shape through discoveries from the Cairo Genizah, and this article will add new details to our understanding of his life and work.

 

I. Research Background

Hartwig Hirschfeld first brought attention to this figure when he published a fragment of his Arabic work on the soul (Maqāla fī al-nafs) from Cambridge manuscript T-S 10Ka4.4.1 Despite the fragment's damaged condition, Hirschfeld recognized its importance as it revealed a new name in Judeo-Arabic literature. According to Hirschfeld, the work on the soul shows clear influence from Ibn Sīnā's psychology.2 Like other Jewish Aristotelian scholars, Rabbi Isaiah interprets philosophical ideas through biblical verses, finding support for his concepts in scripture. For example, based on the verse "Who makes the winds His messengers" (Psalms 104:4), he discusses the nature of angels, determining that "God is the creator of the angelic spirits, which are simple substances or abstract souls without any material component".3

The precise identification of Rabbi Isaiah was subject to scholarly debate. Samuel Poznanski noted that there were two individuals by this name – one being Maimonides' brother-in-law and the other his wife's grandfather and it was difficult to determine which of them authored the treatise on the soul.4 He may have also served as head of the ancient synagogue in Dammūh,5 Egypt,6  where pilgrims would visit on the 7th of Adar, the anniversary of Moses' death.7This synagogue later became a central location for the pietistic-Sufi circle in Egypt, after the surrounding lands were purchased by Mishaʾel ben Isaiah, and served as a place of seclusion for figures such as Ḥananel ben Samuel, father-in-law of Abraham Maimonides, and Rabbi Obadiah, son of Abraham Maimonides.8 The Levi family, to which Rabbi Isaiah belonged, traced their lineage to the Palestinian Geonim and bore the title "Head of the Yeshiva of the Pride of Jacob".9 The genealogical records of the al-Thiqah family appear in two Genizah fragments with variations between them, which have been discussed in scholarship.10

 

II. Discovery of a Second Work by Rabbi Isaiah – The Wine Treatise

The discovery of a second work by Rabbi Isaiah, dealing with wine and intoxication (Maqāla al-khamr), preserved in several manuscripts, helps resolve this question. This work was mentioned in a medieval book list published in "The Jewish Library in the Middle Ages"11 but until now no content from it had been identified. Several Genizah fragments of the work have now been identified, with one containing an introduction similar to that of the soul treatise, and another containing quotations from Saadia Gaon's commentary on Parashat Shemini and from Moses ibn Ezra's "Kitāb al-muḥāḍara wa-l-mudhākara".12

The citation of Moses ibn Ezra (1055–1140) in the wine treatise provides chronological evidence that suggests identifying the author as Maimonides' brother-in-law (1138–1204) rather than his wife's grandfather, though this identification cannot be considered definitive.

While the authorship of both works can be attributed to Rabbi Isaiah through the evidence presented above, the manuscripts themselves were copied by the same scribe, despite showing notable differences in format and preservation. The soul treatise was written on small-format folios, each containing 13 lines of text – a format sometimes associated with personal copies or study texts. In contrast, the wine treatise was produced on standard-size folios with approximately 23 lines per page, suggesting a more formal presentation copy. These differences in format might reflect different intended audiences or purposes, even though both texts were copied by the same hand. 

The faded condition of the Maqāla al-khamr has previously prevented scholars from deciphering its opening lines and identifying its author. However, a careful comparison with the opening lines of the Maqāla fī al-nafs allows us to reconstruct the damaged text with confidence. As shown in the images presented here [Figures 1 and 2], the parallel structure of both openings follows the same formulaic pattern typical of medieval Arabic literary compositions. 

 

JTS MS JTS ENA 2986.8 recto

Figure 1: Opening of the Wine Treatise, JTS ENA 2986.8 r

 

T-S 10Ka4.4 1v

Figure 2: Opening of the Soul Treatise, T-S 10Ka4.4 f.1v

 

The identification of these manuscripts' scribe adds another element to their transmission history. Based on paleographic analysis, Amir Ashur has suggested that the handwriting matches that of Abū Naṣr ibn al-Ṭabīb, whose letter is preserved in T-S 8J15.13.13 This identification may help illuminate the circumstances of these works' copying.

The letter provides evidence of Abū Naṣr's situation and his connection to the al-Thiqah family:

"Your servant Abū Naṣr ibn al-Ṭabīb.

Your servant has received your honored note – may I never lack your beneficence and companionship.

(Your note) was accompanied by the note of al-Shaykh Abū al-Maʿālī – may God perpetuate his glory – that indicates a favourable opinion of your servant, and this is due to your excellent mediation and noble intention. I have written him a response accompanying this note. My master should read it and speak with him after reading it, perhaps he will choose what I have explained to him and grant what he shall decide. I hope that when I can show my face again14 and I have overcome this crisis, I will be able to achieve my release and find means for it. I have informed him that I call God to witness that I seek nothing more than bread to eat and clothing to wear [in Hebrew: לחם לאכול ובגד ללבוש],15 and my wife is in the same situation until God relieves us from this hardship. I have not heard from him after that – let me know. I wish to meet with you again, for since the time I met with you, I have been hopeful for good and my soul has been certain of well-being, due to your good intention and your knowledge of my situation and what has befallen me before and after. The delay in responding to the notes was only due to the difficulty of finding paper and a leaf in the place where I am."

The letter documents Abū Naṣr seeking employment through an intermediary who might recommend him to Abū al-Maʿālī. This Abū al-Maʿālī may be identified as Abū al-Maʿālī ibn Mishaʾel, Maimonides' brother-in-law, as T-S 8K22.6 informs us that Isaiah's kunya was Abū al-Maʿālī. However, it should be noted that Abū al-Maʿālī is a rather common name in this period, which makes this identification tentative. Abū Naṣr mentions writing a direct appeal to Abū al-Maʿālī, which accompanied this letter ("I have written him a response accompanying this note").

If Abū Naṣr indeed copied these treatises, as the paleographic evidence suggests, this would add to our knowledge of his scribal work, which included Bible commentaries and other texts. The letter provides a glimpse into the economic circumstances of a learned individual who earned his living through copying manuscripts, while also illuminating the broader social context in which medieval Jewish philosophical works were produced and transmitted.

 

III. Edition of the Wine Treatise's Introduction

The opening section of the Maqāla al-khamr provides valuable insights into both its structure and purpose. Despite the manuscript's damaged condition, we can reconstruct its contents with considerable confidence through comparison with the author's other extant work, the Maqāla fī al-nafs (Treatise on the Soul). The treatise begins with a formal introduction typical of medieval Judeo-Arabic literary compositions, followed by a detailed outline of its five chapters. Below is an edition of the opening section and its chapter list, with translation and commentary:

 

ENA 2986.8 r

1. [מקאלה אלכ'מר]

2. [ממא עני] ב[ג]מעה [מן כלאם אלעלמא]

3. ישעיהו הלוי בר [מיש]אל

4. ז"ל עם חסידי ישראל

5. סאלתני יאכ'י אבקאך אללה בקא מן אר֯[אד]

6. מן אראד ארשאדה ותופיקה וחיאנ֯תה לד֯[יה]

7. ותגריד נעמה ומזיד אחסאנה לדי֯ך֯ כר[אמה]

8. אלכ'מר ומא קיל פי מנאפעה ומא קיל [פי פצ'אילה]

9. פאעלם אן מקאלתי הד'ה תשתמל עלי [כ'אמס אלבאב]

10. אלבאב אלאול מא קיל פי מנאפעה

11. אלבאב אלת'אני מא קיל פי מדחה

12. אלבאב אלת'אלת' מא קיל פי דמה מן /ג'הה\ אלשרע

13. אלבאב אלראבע מא קיל פי דמה מן ג'הה אלנקל

14. אלבאב אלכ'אמס מא קיל פי דמה מן כלאם אלעלמא

15. פאקול אולא אן אללה גל ועלא אגלא֯ל֯ה֯ אעטאנא אלעקל וחבבנא פ֯י֯ה֯

16. לננאל ונבלג גאיה מא פי ג'והר מת'לנה עלה ובלוגה. ואנה תעטם

17. נעמה ענדנא ואנפע אלאשיא לנא ואג'ד֯אנא עלינא ובה פצ'לנא

18. עלי אלחיואן אלגיר נאטק חתי ססנאהא ודלאלנאהא ומלכנא

19. וערפנאהא פי אלוגוה אלעאידה עלינא מנאפעהא ובה [נ]ד[רך]

20. ג'מיע מא ירפקנא ויחסן ויטיב בה עישנא.

 

Translation:

1.    [Treatise on Wine]

2.    [From what was] compiled [from the words of the sages]

3.    Isaiah HaLevi bar [Mish]ael

4.    Of blessed memory, with the pious of Israel

5.    You asked me, my brother – may God preserve you as He preserves those whom He wishes

6.    to guide and bestow favor upon and his sustenance with [Him]

7.    and the increase of His grace and the addition of His gifts for your [honored] sake

8.    concerning wine and what has been said about its benefits and what has been said [in its praise].

9.    Know that this treatise of mine contains [five chapters]:

10.    The First Chapter – What has been said of its benefits

11.    The Second Chapter – What has been said in its praise

12.    The Third Chapter – What has been said against it from the perspective of religious law

13.    The Fourth Chapter – What has been said against it from the perspective of tradition

14.    The Fifth Chapter – What has been said against it from the words of the sages

15.    First I say that when God – exalted and elevated is His majesty – gave us intellect and made us fond of it 

16.    to attain and reach the ultimate goal that exists in the essence of what resembles it, its cause and its attainment. And He magnified

17.    His grace upon us and made it the most beneficial of things for us and the most suitable for us, and through it He distinguished us

18.    from the non-speaking animals until we governed them and guided them and ruled them

19.    and we came to know them in the ways that their benefits return to us, and through it [we comprehend]

20.    all that assists us and improves and makes good our life.

 

This introduction reveals several important features of medieval Jewish scholarly writing: the formal literary address, the systematic organization of the material into defined chapters, and the philosophical framework that emphasizes the role of divine-given intellect in human understanding. The treatise's structure, moving from benefits and praise to various forms of criticism, suggests a comprehensive and balanced approach to the topic of wine in medieval Jewish thought.

Like other works written by Jewish thinkers since the tenth century, both in halakhic and philosophical domains, the introduction shows clear influence of kalām theology in its treatment of divine beneficence, the uniqueness of the soul, and the supremacy of intellect. This reflects the broader intellectual context in which medieval Jewish scholars engaged with Islamic theological concepts and methodologies.

The surviving fragments of both the wine treatise and the soul treatise suggest that these works were primarily compilations from earlier sources, similar to Moses ibn Ezra's al-Ḥadīqa fī maʿnā al-majāz wa-l-ḥaqīqa, which Isaiah himself quotes. As Shlomo Pines noted regarding Ibn Ezra's work, the abundance of quotations, while reflecting a certain lack of philosophical originality, gives the text its significant value in preserving citations from earlier thinkers.16

The wine treatise should be understood within the rich tradition of Arabic writing about wine, both in its literary and scholarly aspects. This tradition has been extensively studied by modern scholars, particularly in relation to its development in post-classical Arabic literature and its broader cultural significance in medieval Islamic society.17

 

IV. Additional Fragments from the Book of the Soul

Several additional fragments of the Kitāb al-nafs have been identified, expanding our knowledge of the work's scope and sources.18 These fragments consistently demonstrate the author's reliance on Saadia Gaon's writings, reinforcing the work's connection to earlier Judeo-Arabic philosophical traditions.

Of particular interest is fragment T-S Ar.43.121, which contains a previously unknown reference to an early philosophical work:

קאל בעץ֗ אלמתשרעין ידעא בטאבא בן אלצלחון אלצואף פי כתאבה אלמלקב בכתאב אלמנאט֗ר אלמטאלעה מנה אלי עלום שתי גלילה שריפה ... אלאנואע

"Said one of the religious law scholars (mutasharriʿīn), known as Ṭāba ibn al-Ṣalḥūn al-Ṣawwāf, in his book entitled Kitāb al-manāẓir that its study leads to various noble and elevated sciences... types."

 

T-S Ar.43.121

Figure 3: From the Soul Treatise, T-S Ar.43.121 recto

 

This citation is significant as it provides the earliest known reference to the Kitāb al-manāẓir, a work preserved in the St Petersburg manuscript EVR ARAB I 1679. This manuscript, comprising 78 folios, represents approximately one-third of the complete work. According to the author's own testimony, the work was completed in Mosul in 372 AH (983 CE), and this copy was made in 1442 SE (1131 CE). The Kitāb al-manāẓir has been extensively studied by Haggai Ben-Shammai in two detailed studies.19 This citation in Rabbi Isaiah's work provides a valuable early attestation of the text in medieval Jewish literature. This discovery not only helps date the manuscript's reception among Jewish readers but also suggests the channels through which philosophical works circulated between Jewish communities in Iraq and Egypt.

The reference appears within a broader discussion of epistemology and the classification of sciences, typical of medieval Arabic philosophical discourse. Its inclusion in the Kitāb al-nafs indicates that Rabbi Isaiah had access to a broad range of philosophical sources beyond the better-known works of Saadia Gaon and other mainstream Jewish philosophers. This evidence supports recent scholarly arguments for a more complex and diverse intellectual network in medieval Jewish thought than previously recognized.

 

V. Conclusions

This study has contributed several new elements to our understanding of medieval Jewish intellectual history through the examination of Rabbi Isaiah HaLevi ben Mishaʾel's works and their transmission. The evidence presented allows us to draw several significant conclusions while also highlighting areas for future research.

First, the identification of the Maqāla al-khamr adds a previously unknown work to Rabbi Isaiah's corpus. This discovery, alongside new fragments of the Maqāla fī al-nafs, expands our knowledge of the scope and nature of philosophical writing in the Maimonidean circle. The systematic treatment of wine in multiple contexts – religious law, philosophy, and adab literature – demonstrates how medieval Jewish scholars participated in the broader cultural discourse of their time, integrating traditional religious perspectives with philosophical methodology and literary conventions.

Second, the paleographic identification of Abū Naṣr ibn al-Ṭabīb as the scribe of both works provides insight into the social and economic aspects of manuscript production in medieval Egypt. His correspondence seeking employment illuminates the networks of patronage that supported scholarly activity and text transmission. This finding contributes to our understanding of how philosophical works were commissioned and copied in medieval Jewish communities.

The citation of Ṭāba ibn al-Ṣalḥūn's Kitāb al-manāẓir in the Maqāla fī al-nafs illuminates the broader intellectual networks through which philosophical texts circulated between Jewish communities in Iraq and Egypt, suggesting that scholarly exchange was more extensive than previously recognized.

These conclusions point to several directions for future research. The relationship between Rabbi Isaiah's philosophical works and those of his contemporaries, particularly within the Maimonidean circle, deserves further investigation. Additionally, the wine treatise's systematic treatment of its subject matter might provide a model for understanding how other medieval Jewish scholars approached similar topics. Finally, the identification of Abū Naṣr as scribe suggests that a broader examination of scribal practices and patronage networks in medieval Egypt might yield further insights into the transmission of philosophical texts.

This study thus contributes not only to our knowledge of a specific figure in medieval Jewish thought, but also to our understanding of how philosophical works were composed, transmitted, and preserved in medieval Jewish society. The evidence from the Cairo Genizah continues to illuminate the complex intellectual and social networks that characterized medieval Mediterranean Jewish culture.

 


Footnotes

1 Hirschfeld, H., "The Arabic Portion of the Cairo Genizah at Cambridge", Jewish Quarterly Review, Vol. 17 (1904), pp. 65–68.

2 Ibid., p. 67: "The author evidently drew upon Ibn Sīnā's Psychology".

3 Ibid.: "God is the creator of the angelic spirits, which are simple [substances] or abstract souls without any material component part".

4 Poznanski, S., "Deux listes commémoratives de la Gueniza", Revue des Études Juives, 66 (1913), pp. 60–74. Assaf, in his Sources and Studies in Jewish History (Hebrew), Jerusalem, 1946, p. 157, believes that Maimonides' wife's grandfather was the author of the book on the soul, basing this on Freimann who relied on Poznanski, who himself was uncertain about the matter.

5 On this synagogue and the spelling of its name see Friedman, "Geniza Studies and Maimonidean Research", in: M.A. Friedman (ed.) Maimonides and the Cairo Geniza, Jerusalem 2024, p. 209, n. 526

6 Assaf (above, n. 4) determines that a letter concerning the leasing of a synagogue with the consent of its head, "Our master and teacher, our elder and great one Isaiah HaLevi the wise and understanding, son of the honored, great, and holy one, our prince and great one, our esteemed Misha'el the wise and understanding, may the memory of the righteous be blessed" preserved in Cambridge T-S 10J4.11, certainly refers to the first Isaiah "who was an honored sage and the titles by which he is described in this document suit him more than his grandson, about whom we know nothing." However, if we assume the second Isaiah was the author of the book on the soul and more, these titles would suit him as well.

7 Joseph Sambari, Divrei Yosef, ed. Shimon Shtober (Jerusalem: Ben-Zvi Institute, 1994), pp. 158-160. For an extensive discussion of this synagogue, see Assaf (above, n. 4), pp. 18–25.

8 Seewald, Y., The Ancient Synagogue of Dammūh as a Place of 'Perfect Seclusion' for Egyptian Pietists (Hebrew) (forthcoming).

9 Poznanski (above, n. 4), pp. 71–72.

10 The list in Cambridge T-S 8K22.6 was published by J. Mann, The Jews in Egypt, II, p. 319, and again by A.H. Freimann, "The Genealogy of Maimonides' Family", Alumah 1 (1936), p. 11. Corrections to this list, and also the list in Cambridge T-S K15.68, were published by S.D. Goitein, "Rabbi Abraham Maimonides and his Pietist Circle"' Tarbiz 33 (1964), p. 181. A family tree (without Goitein's corrections) appears at the beginning of Freimann's article. There is also a third family list in T-S 12.343; for a comprehensive and updated discussion of this list, along with a broader analysis of Maimonides' father-in-law's family genealogy and the identification of the two individuals named Misha'el ben Isaiah in this lineage, see Seewald, Y., "The Family of Maimonides' Father-in-Law and Rabbi Isaiah ben Misha'el the Pious" (Hebrew), Toladot: A Blog for Genealogical Research, ed. B. Panteliat (December 2024), available at https://toladot.blogspot.com/2024/12/blog-post.html

11 Allony, N., The Jewish Library in the Middle Ages: Book Lists from the Cairo Genizah (Hebrew), Jerusalem: Ben-Zvi Institute, 2006, p. 337.

12 The beginning of the work with its title is preserved in ENA 2986.8 (it appears that Halkin used it in his edition of Kitāb al-muḥāḍara wa-l-mudhākara, where it is manuscript ס in his list on p. 312, though erroneously written as 2906 instead of 2986, and he did not notice that folios 4–5 are not connected to folio 8, the former being from Kitāb al-muḥāḍara itself, and folio 8 being from the wine treatise quoting from it), and additional fragments from the same copy in ENA 2708.32, through which we have been able to complete many lacunae in Saadia's commentary on Parashat Shemini, preserved in a folio that was the outer leaf of a quire and was severely damaged with many holes, and Cambridge T-S NS 312.125.

13 Personal communication from Dr Amir Ashur, December 30, 2024. I am grateful to Dr Ashur for sharing this identification.

14 The Arabic phrase "kashf al-wajh" (lit. 'unveiling of the face') is a common idiom in medieval Arabic letters expressing the writer's hope to overcome shame or disgrace, particularly in the context of financial difficulties.

15 A direct quote in Hebrew from Genesis 28:20, Jacob's vow at Bethel. The use of biblical Hebrew in this otherwise Judeo-Arabic letter emphasizes the petitioner's modest requests.

16 Pines, S., Between Jewish Thought and the Thought of the Nations (Hebrew) (Jerusalem, 1977), p. 44.

17 See particularly Van Gelder, G.J., "A Muslim Encomium on Wine: 'The Racecourse of the Bay (Ḥalbat al-Kumayt)' by al-Nawāǧī (d. 859/1455) as a Post-Classical Arabic Work", Arabica (1995): 222– 234; and idem, Of Dishes and Discourse: Classical Arabic Literary Representations of Food (London: Routledge, 2014).

18 These are from Cambridge: T-S Ar.7.15; T-S Ar.43.121; T-S Ar.44.119; T-S Ar.49.12; T-S Ar.44.118 (11 lines instead of 13, but dealing with the same topics and also frequently using "wa-'lam yā akhī"); from JTS in New York: ENA 2949.21. Questionable fragments: Cambridge T-S AS 163.134; T-S AS 154.103.

19 Ben-Shammai, H., "A Circle for Philosophical Bible Study in Tenth Century Mosul" (Hebrew), Pe'amim 41 (1990), pp. 21–31; idem, "A Jewish Wool Merchant in Tenth-Century Mosul Defends Resorting to 'the Sages of the Nations': An Early Encounter between Jewish Bible Exegesis and Graeco-Arab Philosophy", in Pesher Nahum: Studies in Jewish Exegesis, Theology, and History in Memory of Norman Golb, ed. E. Greenstein et al. (Chicago, 2012), pp. 11–32.

 


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