<p>Sifra is the earliest extant rabbinic commentary on the book of Leviticus. On a basic level, Sifra presents and validates rabbinic law, but this was done by creating a link between a proposition, halakhic or not, and a scriptural passage. Scholars in the last few decades-including Neusner and Stemberger-have debated Sifra's relationship to Mishnah-Tosefta. Howard Apothaker demonstrates that the set of rules in Dibbura deSinai on topics shared...