Sela on Rabbi Abraham Ibn Ezra, 'Sefer ha`ibbur: A Treatise on the Calendar by Rabbi Abraham Ibn Ezra'

Rabbi Abraham Ibn Ezra
Shlomo Sela

Rabbi Abraham Ibn Ezra. Sefer ha`ibbur: A Treatise on the Calendar by Rabbi Abraham Ibn Ezra. Translated and Annotated by Mordechai S. Goodman. Jersey City: KTAV Publishing House, 2011. 300 pp. $59.50 (cloth), ISBN 978-1-60280-160-8.

Reviewed by Shlomo Sela (Bar-Ilan University) Published on H-Judaic (February, 2012) Commissioned by Jason Kalman

Abraham Ibn Ezra and the Jewish Calendar

The calendar was always high on the agenda of educated Jewish audiences in the Middle Ages. The ritual and social connotations of the calendar had enormous consequences for the collective religious awareness of medieval societies, and all the more so for the national identity of a minority medieval community. By the tenth century, a stable perpetual calendar had been promulgated, superseding the ad hoc determination of new moons and intercalations by the supreme religious court in Roman Palestine. Even though there was very little to add to these rules, eleventh- and twelfth-century Spanish Jewish intellectuals of the Rabbanite camp, such as Abraham Bar Hiyya (ca. 1065–ca. 1136), Abraham ibn Ezra (ca. 1089–ca. 1161), and Maimonides (1138–1204), made a significant contribution in this field. They began to write about the calendar in Hebrew, an innovation that made it possible for their work to cross the cultural and linguistic borders between the eastern and western Jewish communities. On the one hand, they reverted to what they deemed as the ultimate sources of Jewish law, in order to strengthen and safeguard the Jewish calendaric regulations as they knew and described them. On the other hand, they explained the foundations of the Jewish calendar by implementing the tools provided by the new Greco-Arabic astronomy with whom Andalusian intellectuals had become acquainted. The latter point is our main justification for designating their calendaric work as scientific.

Ibn Ezra owes his reputation to his outstanding biblical commentaries, but he also wrote religious and secular poetry; monographs on theology and grammar; and a large corpus of treatises on astrology, astronomy, mathematics, and the Jewish calendar. His contribution to the last of these was immense and influential. In contrast with Bar Hiyya and Maimonides, he addressed calendar issues in his biblical commentaries.[1] In addition, ibn Ezra wrote several works in Hebrew, devoted specifically to the Jewish calendar. There are two versions of Sefer ha‘Ibbur (Book of intercalation). The first was composed in Verona in 1146; the second, now lost, was written in Provence somewhat later. He also wrote responsa to three questions submitted to him by David ben Joseph of Narbonne, presumably when he lived in that town between 1148 and 1153. Finally, in December 1158, somewhere in England, ibn Ezra wrote Iggeret ha-Shabbat (The epistle on the Sabbath), in which, behind the fictional veneer of replying to the Sabbath’s grievance against him, he dealt with the three chief calendrical periods: the year, the month, and the day.[2] Ibn Ezra also devoted parts of Liber de rationibus tabularum (Book of the reasons behind astronomical tables, a Latin work written in two versions that modern scholarship has assigned to him although it may originally have been written in Hebrew and subsequently translated into Latin) to present before Christian readers the points of contact linking the Jewish and the Christian calendars, and presumably also parts of the two versions of the lost Hebrew counterpart Sefer Ta’amei ha-Luhot (Book of the reasons behind astronomical tables), to deal with the astronomical aspects of the Jewish calendar.[3]

Mordechai S. Goodman has now provided us with the first annotated English translation of ibn Ezra’s Sefer ha‘Ibbur.[4] The translation is idiomatic and clear. Even though he does not always stick as closely to the Hebrew text as might be desired, only a translator proficient in the technicalities of the Jewish calendar (as Goodman clearly is) could have done justice to such a convoluted medieval text. This is not a conventional critical edition, to say the least. Although Goodman says that he used seven different manuscripts of Sefer ha‘Ibbur, he has not produced a significant improvement on S. Z. H. Halberstam’s edition (1874). The Hebrew text is not accompanied by variae lectiones, and only occasionally do the annotations offer variant readings of isolated words or expressions. In the vast majority of cases, the notes below the Hebrew text offer conventional explanations just as those found below the English translation. One wonders why this duplication was necessary. The English translation is followed by eight appendices and a glossary of technical terms, which are very useful for understanding the text.

Here and there it is obvious that this edition of Sefer ha‘Ibbur was produced in isolation from current ibn Ezra scholarship. Goodman does not seem to be aware that our knowledge of ibn Ezra’s work and thought has grown apace in the last few years. Almost all the entries in his bibliography belong to the twentieth and nineteenth centuries. For example, according to the translator’s preface, only a fragment of the third chapter of Sefer ha‘Ibbur is extant; but there is no source note for this statement. The last page of the Hebrew text is a short fragment of that third chapter. In fact, it is only the first part of a larger fragment that was identified a few years ago, parts of which have been already published and translated.[5]

These caveats aside, this new edition and translation of ibn Ezra’s Sefer ha‘Ibbur, particularly the translation and appendices, is a valuable contribution to the field. As such, it will serve as an important tool for students of the Jewish calendar in general, and of the work and thought of the twelfth-century polymath ibn Ezra, in particular.


[1]. See, for example, prefaces of the short and long commentaries on the Pentateuch; long commentary on Exod. 12:2; Lev. 23:4, 23:24, and 25:19; Ps. 81:4 and 104:19; Esth. 9:22; etc.

[2]. See Shlomo Sela and Gad Freudenthal, “Abraham Ibn Ezra’s Scholarly Writings: A Chronological Listing,” Aleph 6 (2006): 13–55, esp. 19–22, 32, 36, and 46–47.

[3]. José M. Millás Vallicrosa, ed., El Libro de los Fundamentos de las Tablas Astronómicas de R. Abraham Ibn Ezra (Madrid and Barcelona: CSIC, 1947), 75–76, 98–100.

[4]. Goodman has also translated ibn Ezra’s Iggeret HaShabbat (The Sabbath Epistle of Abraham of Rabbi Abraham Ibn Ezra) (Jersey City: Ktav, 2009) and has edited an edition of his commentary on the Book of Job, Sefer Iyov im perushei ibn Ezra (Jerusalem: Mossad HaRav Kook, 2009).

[5]. Shlomo Sela, Abraham Ibn Ezra and the Rise of Medieval Hebrew Science (Leiden: Brill, 2003), 42–44.

Printable Version:

Citation: Shlomo Sela. Review of Rabbi Abraham Ibn Ezra, Sefer ha`ibbur: A Treatise on the Calendar by Rabbi Abraham Ibn Ezra. H-Judaic, H-Net Reviews. February, 2012. URL:

This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License.