Time and Difference in Rabbinic Judaism examines how the demarcation of time plays a role in identity construction. Structurally, the book progresses from the broad to the particular, moving from a study of the yearly calendar to the weekly cycle (with an emphasis on the Sabbath) to different ways of marking time within a single day. That trajectory is paralleled by a shift in focus from the external to the internal; while the first two chapters examine how time is used both to construct and reinforce distinctions between Jewish and non-Jewish communities (both Greco-Roman and Christian), the latter two chapters focus on the construction of difference within a Jewish framework (between women and men, as well as between humanity and God). These two progressions are closely related: when the focus is external, Kattan Gribetz emphasizes structures of time that would be visible to all participants, since the rabbis were aware of Greco-Roman holidays and vice versa, but when the focus is internal, her analysis shifts to less visibly time-based rituals, such as the way a woman's daily checking of her niddah status creates gendered experiences of time.

The first part of the book, which looks at how time is used both to construct and to reinforce distinctions between Jews and non-Jewish Romans, as well as between Jews and Christians, offers a rich comparative historical analysis that will be of interest to many students of late antiquity, not just those who study rabbinic culture. The first chapter, “Rabbinic and Roman Time,” provides an accessible explanation of the Roman calendar and its festivals, while also providing a rich analysis of the ways that rabbis reimagined those festivals and their significance. As Kattan Gribetz persuasively shows, the rabbis were deeply embedded in Roman society, even using Roman festivals to demonstrate the truth (and superiority) of Jewish holidays. The evidence demonstrates direct intercultural awareness and engagement. In the second chapter, “Jewish and Christian Time,” Kattan Gribetz wades into more highly disputed territory, arguing that from as early as the third century, rabbinic discussions of Shabbat are in implicit dialogue with Christian writings about (and against) Jewish Sabbath observance, although they do not engage with Christian texts or thinkers explicitly. Such a claim is, by its nature, more difficult to prove, but Kattan Gribetz advances a plausible and nuanced argument through her study of the Mekhilta's treatment of Shabbat and acknowledges possible alternative explanations, noting that the text repeatedly “struggles with ideas firmly based in second- and third-century anti-Jewish Christian theological works, though it is difficult to definitively conclude whether it was responding to such claims” (117).

The second part of the book, which looks at how time is used to construct distinctions within the Jewish community (predominantly between men and women) and to understand the relationship between humanity and God, shifts to focus exclusively on rabbinic sources, and thus will be of particular interest to students of rabbinic literature and culture. The third chapter, “Men and Women's Time,” draws a novel comparison between the daily practice of reciting the Shema, which comes to be gendered as male (although women may also recite it), and the daily practice of checking one's bodily purity status, which comes to be gendered as female and associated specifically with menstrual purity. This comparison is especially provocative because the recitation of the Shema is halakhically categorized as a time-bound commandment, a category of obligations that are triggered at specific times of day and from which women are considered exempt under Jewish law. Why, then, is the process of checking one's niddah (menstrual purity) status, which also happens every morning and night, not considered a time-bound commandment? Kattan Gribetz argues that although “it is not clear why rabbinic sources do not understand menstrual purity laws also as positive timebound commandments,” the effect of this category and its gendered distinctions was “the bifurcation of time for men and women, as well as the association of men and women's bodies with different types of time” (138). While both ritually and conceptually fascinating, the treatment of time and its impact on identity construction in this chapter is notably different from the rest of the book, as the rabbis here do not have an Other who is a clear interlocutor. The conversation is completely internal; while much of it may be about women, it is both by (male) rabbis and for (male) rabbis. As a result, the way that time is used to draw distinctions between groups in the Shema and niddah examples is importantly different from the examples discussed in the proceeding chapters, and it would have been helpful for this difference to be addressed more explicitly.

While the fourth chapter, “Human and Divine Time,” also examines a completely internal conversation (by rabbis, for rabbis) it returns, nonetheless, to the more outward focus of the first two chapters. Even though the God imagined in these texts is a rabbinic construction, God retains an independence that seems absent from the discussions of women and gendered time. As Kattan Gribetz notes, “rabbinic sources imagine a God whom humans might wish to emulate but, ultimately, one whom they cannot fully resemble or understand. Imagining human and divine time thus becomes an avenue through which rabbinic sources articulate ideas about human-divine similarity and difference” (190). As a result, even though it looks solely at rabbinic sources, this chapter brings the thematic focus of the book back to where it started. Just as the rabbis are invested in the Roman calendar, using it to construct and articulate a particular understanding of the rabbinic-Roman relationship, so too they imagine that God is invested in the ways that people divide up their daily calendars and they explore God's own daily calendar as a way of better understanding the divine-human relationship.

Throughout Time and Difference in Rabbinic Judaism, Kattan Gribetz shows herself to be both an astute and nuanced reader of texts, drawing out the various historical, cultural, and religious dynamics that motivate these conversations. Her analysis of the way time is constructed brings coherence and focus to a remarkable breadth of material, and the book offers an insightful framework for thinking about rabbinic literature and the construction of identity in late antiquity. The introduction and conclusion to the book (“Temporal Legacies”) collectively offer a compelling picture of the ongoing relevance of this time-based analytic framework and provide tantalizing suggestions for how it might be applied to the study of both medieval and modern Judaism.