What is "sifra"

Sifra ( Aramaic: סִפְרָא) is the Halakic midrash to Leviticus. It is frequently quoted in the Talmud, and the study of it followed that of the Mishnah, as appears from Tanḥuma, quoted in Or Zarua, i. 7b. Like Leviticus itself, the midrash is occasionally called "Torat Kohanim" ( Ḳid. 33a; Sanh. 103b; Cant. R. vi. 8), and in two passages also "Sifra debe Rab" ( Ber. 11b, 18b). According to Leḳaḥ Ṭob (section צו), this latter title was applied originally to the third book of the Pentateuch because Leviticus was the first book studied in the elementary school, and it was subsequently extended to the midrash; but this explanation is contradicted by analogous expressions such as "Sifre debe Rab" and, in a broader sense, "ketubot debe Rab" ( Yer. Ket. 26c) and "teḳi'ata debe Rab" (Yer. Ab. Zarah 39c).