The Rabbinic Ban on Ma’aseh Bereshit: Sources, Contexts and Concerns YAIR FURSTENBERG Early rabbinic writings – Mishnah, Tosefta and Tannaitic Midrash – ex- plicitly restrict the exploration of the creation story or the investigation of the period before “God created man on earth” or beyond “one end of heaven to the other.” The date and origin of this ban, however, is shrouded in fog, and much of our knowledge of this issue, including debates, exam- ples and justifications, derives only from later amoraic sources: the two Talmuds and Genesis Rabbah. In the case of a sensitive issue such as crea- tion, anxieties may change and new religious and intellectual challenges arise. We cannot therefore assume that the concerns of the third and fourth-century Amoraim represent the original meaning and purpose of the ban, and research of its origins inevitably necessitates a separate inquiry into the earliest sources at our disposal. The tannaitic sources are extremely slim, however. 1 Therefore, any such inquiry depends first and foremost on the choice of a corpus against which these rabbinic sources are to be read. Prima facie, a most relevant text, which can arguably elucidate the rabbinic apprehension, is Irenaeus’ attack against the heretical practices of Genesis exegesis, as he spells out the dis- astrous results of unrestrictedly expounding the creation story: Every one of them [the heretics] generates something new, day by day, according to his ability; for no one is deemed ‘perfect’ who does not develop among them some mighty fictions. Moses, then, they declare, by his mode of beginning the account of the creation, has at the commencement pointed out the mother of all things when he says ‘In the be- ginning God created the heaven and the earth’; for, as they maintain, by naming these four: God, Beginning, Heaven and Earth, he set forth their Tetrad. 2 According to Irenaeus’ description of Valentinian theology, Bythus and Sige, Nous and Aletheia, which stand at the head of the creation story, 1 Alon Goshen-Gottstein, “Is Ma’aseh Bereshit part of Ancient Jewish Mysticism?” JJTP 4 (1995): 185. 2 Irenaeus, Haer. 1.18.1 (ANF 1.343).