Bava Kamma 18B

מי שמעת ליה?

did you hear him distinguish between the different parts of the payment? There is no aspect of innocuousness in the case of pebbles.

אלא כי קאמר רבי אלעזר נזק שלם ⁠– כגון דאייעד; ובהא קמיפלגי ⁠– מר סבר יש העדאה לצרורות, ומר סבר אין העדאה לצרורות.

Rather, when R' Elazar says that the owner of the dog pays the full cost of the damage in a case that is similar to one of propelled pebbles, he was referring to a case where the owner of the animal was forewarned with regard to this matter. And they disagree about this point: One Sage, R' Elazar, holds that there is forewarning with regard to propelling pebbles; therefore, if there was testimony given in court that a particular animal regularly propels pebbles in the course of its walking, the animal is deemed forewarned and its owner pays the full cost of the damage. And one Sage, the first tanna, holds that there is no forewarning with regard to pebbles. Apparently, payment for damage caused by pebbles is paid from the body of the animal.

אלא הא דבעי רבא: יש העדאה לצרורות, או אין העדאה לצרורות? אי לרבנן ⁠– אין העדאה לצרורות, אי לרבי אלעזר ⁠– יש העדאה לצרורות!

The Talmud asks: But if this is the case, then the dilemma raised by Rava concerning whether there is forewarning for propelling pebbles or there is no forewarning for propelling pebbles, can be resolved from this dispute. If the dilemma is raised according to the Rabbis, i.e., the first tanna, there is no forewarning for propelling pebbles. If the dilemma is raised according to R' Elazar, there is forewarning for propelling pebbles.

אמר לך רבא: כי מיבעיא לי לדידי, אליבא דרבנן דפליגי עליה דסומכוס; אבל הכא, בין לרבנן בין לרבי אלעזר ⁠– כסומכוס סבירא להו, דאמר: צרורות ⁠– נזק שלם משלם.

The Talmud answers that Rava could have said to you: When I raise the dilemma, I do so specifically according to the opinion of the Rabbis who disagree with Sumakhos and hold that one pays half the cost of the damage in the case of pebbles; but here in this baraita, both the Rabbis, i.e., the first tanna, and R' Elazar hold in accordance with the opinion of Sumakhos, who says that in the case of pebbles, one pays the full cost of the damage.