The principle that the Torah allows reliance on probability in cases of doubt is found in numerous Talmudic passages. The sugya we here examine –Ḥullin 11a–12a – is concerned with the derivation of the principle from Scripture. What is the Scriptural warrant for relying on probability rather than demanding certainty? The term rubba is in Aramaic (Hebrew: rov) with the meaning of ‘majority’, hence the majority or most likely opinion. It can be translated literally into English as ‘majority’ but in most instances the word ‘probability’ comes nearest to the meaning. The sugya does not question the application of the principle. That is everywhere assumed. Its concern is solely with the question of Scriptural authority for the principle.

The sugya first sets the stage for the discussion. The opening words are: ‘How do we know that which the Rabbis say: “Follow [lit. ‘go after’] probability” [rubba]?’ The Talmud immediately interjects: how can you ask, ‘how do we know?’; surely there is no problem since Scripture states explicitly: ‘Turn after the majority’ (Exodus 23: 2)? That is to say, the Talmud is puzzled by the request for Scriptural warrant for the principle, as if this were unclear. There is an explicit verse which states that rubba is followed. (Actually, the plain meaning of the verse, in its context, is ‘Do not turn after the majority to do evil’ but in its traditional, Rabbinic, interpretation is: ‘Do not follow a multitude to do evil (but otherwise) turn after the majority’.)