All cultures, religions, and ethical or legal systems struggle with the role intention plays in evaluating actions. The Talmud compellingly elaborates on the notion of intention through the radical concept that “A sin committed for the sake of God [ averah li-shmah ] is greater than a commandment fulfilled not for the sake of God [ mi-mizvah she-lo li-shmah ].” The Babylonian Talmud attributes this concept, which challenges one of rabbinic Judaism’s most fundamental dogmas, the obligation to fulfill the commandments and avoid sin—to R. Nahman b. Isaac (RNBI), a renowned 4th century Amora. Considering the normative character of the rabbinic culture in which Halakhah (Jewish religious law) plays such a central role, this concept, seems almost like a foreign body in the Talmudic corpus. The book reveals the origins of this radical idea, its accurate meaning and use in the time this concept was formulated and the movement of this radical idea from the margins culture to mainstream - into the Babylonian Talmud, the canonic book of Rabbinic Judaism. The findings of this research provide substantial insight into our understanding of the interpretive process and of conceptual adaptation in rabbinic culture.