Source: Talmud Bavli Berakhot 28b-29a; Tosefta Berakhot 3:25; Cairo Geniza manuscript of the Amidah (discovered 1896).

The Birkat HaMinim (‘blessing of the minim/sectarians’ — a euphemism, since it is actually a curse) is the 12th of the 18 benedictions of the Amidah, the central Jewish prayer recited three times daily. According to Berakhot 28b-29a, Rabban Gamliel II at Yavneh (~90 AD) asked: ‘Is there anyone who knows how to compose a blessing against the minim?’ Samuel the Small composed it. The prayer calls down divine punishment on apostates, informers, and sectarians (minim).

Who were the minim? The term covers multiple groups: Jewish-Christians (Notzrim), Gnostic Jews, and other heterodox Jewish movements. The Cairo Geniza version explicitly names ‘Notzrim’ (Christians) alongside minim. The prayer served as a loyalty test: a Jewish-Christian who led synagogue prayer could not recite a curse against themselves without self-exposure. This is likely the mechanism by which Jewish-Christians were gradually excluded from synagogue worship — a process reflected in the Gospel of John’s references to being ‘expelled from the synagogue’ (John 9:22, 12:42, 16:2).

Scholarly significance: The Birkat HaMinim is central to the ‘Parting of the Ways’ debate — when exactly did Christianity and Judaism become separate religions? J. Louis Martyn’s influential reading of John argues that the Gospel was written in a community actively experiencing expulsion via the Birkat. Others (Boyarin, Lieu) argue the parting was much slower and messier. The prayer also shows that rabbinic Judaism defined itself partly by what it excluded — the formation of orthodoxy always involves the production of heresy.