The impact of purity laws on amoraic laws concerning handling on the sabbath

Dominant in Tannaitic halakhah, the purity laws influenced other fields of rabbinic law. Analysis of the laws of handling objects on the Sabbath – usually termed מוקצה – as a test case shows that the textual legacy of Tannaitic purity laws played a pivotal role in the development of other fields of Amoraic law. This influence is threefold, and can be seen in: (a) cases in Sabbath law modeled upon cases from the Order of Purities in the Mishnah or Tosefta; (b) terminology in Amoraic Sabbath law borrowed from Tannaitic purity laws; (c) principles and distinctions in Sabbath law that seem to be rooted in the purity laws. In some cases, more than one of these aspects can be traced. This phenomenon is extant in various strata of the Yerushalmi and the Bavli. Two complementary explanations are offered for this influence. First, the intertextual character of Amoraic hermeneutics and legal reasoning allowed for utilization of the highly developed purity laws in the expansion of other, less developed, fields of law. Second, the resemblance of the מוקצה laws to the laws of purity led to a deeper influence, thus constructing מוקצה as a “new impurity” as the old system of purity laws was losing its grip.