Study Bava Kamma folio 5B with parallel Hebrew-English text, traditional commentary, and modern study tools. Free access to Babylonian Talmud online.
Let God write only two of the primary categories and derive the other categories from them. Then the tanna says: It is not possible to derive one category from two other categories, as each category has its own unique characteristics, which prevent the derivation of a new category even from a combi
Rava said: And with regard to all of the primary categories in the Mishnah, when you cast the primary category of Pit among them, all of the rest of them can then be derived through an analogy based on the common factor of two categories. This is the case with all of the categories except for Goring
And according to the one who says: On the contrary, Goring is superior in the sense that one’s liability in a case of Goring is more apparent, as the objective of the ox’s action is to cause damage, even Goring can be derived from the common factor of two sources.
The Talmud asks: But if all the categories can be derived from another category and Pit, for the purpose of deriving what halakha did God write all the primary categories explicitly? The Talmud answers: It is in order to derive their unique halakhot that apply exclusively to each category.
Goring is written explicitly in order to distinguish between the halakhot of damage caused by an innocuous animal and damage caused by a forewarned animal.