Reviewed by: Time and Difference in Rabbinic Judaism by Sarit Kattan Gribetz Deborah Barer Sarit Kattan Gribetz. Time and Difference in Rabbinic Judaism. Princeton, NJ: Princeton University Press, 2020. 391 pp. doi:10.1017/S0364009421000179 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. [End Page 442] 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...