Bava Kamma 17B

גמ׳ אמר ליה רבינא לרבא: היינו רגל היינו בהמה! אמר ליה: תנא אבות, וקתני תולדות.

Talmud: The Talmud analyzes the Mishnah: Ravina said to Rava: In the context of the category of Trampling, damage caused by an animal trampling an object with its foot is the same as damage caused by an animal breaking an object with its body. Why does the Mishnah repeat the same halakha twice? Rava said to him: First, the tanna teaches the primary categories of damage, namely the category of Trampling with an animal’s foot, which is mentioned explicitly in the Torah, and then he teaches the subcategories of those primary categories, i.e., the animal is deemed forewarned with regard to causing damage with other parts of its body in the course of its walking.

אלא מעתה, סיפא דקתני: ״השן מועדת״ ״הבהמה מועדת״, מאי אבות ומאי תולדות איכא? הוה קמהדר ליה בבדיחותא, ואמר ליה: אנא שנאי חדא, ואת שני חדא.

Ravina challenges this explanation: If that is so, the latter clause of the Mishnah (19b), which teaches, concerning the primary category of Eating: For what damage caused by Eating is the animal deemed forewarned? It is deemed forewarned with regard to eating food items fit for its consumption, i.e., the animal is deemed forewarned with regard to eating fruits and vegetables. Ravina asks: What primary categories and what subcategories are there in that context? No subcategories of Eating are enumerated there, and nevertheless, the phrase: The animal is deemed forewarned, is repeated. Rava responded to Ravina with a humorous response and said to him: I resolved the difficulty in one Mishnah, now you resolve the difficulty in one Mishnah.

וטעמא מאי? אמר רב אשי: תנא שן דחיה, וקתני שן דבהמה. סלקא דעתך אמינא: ״ושלח את בעירה״ כתיב, בהמה ⁠– אין, חיה ⁠– לא; קא משמע לן דחיה בכלל בהמה.

And what is the reason for the apparent redundancy in the Mishnah with regard to Eating? Rav Ashi said: First the tanna teaches the halakha of Eating by an undomesticated animal and then he teaches the halakha of Eating by a domesticated animal. And it was necessary to state both, as it enters your mind to say that since it is written: “And he set his animal loose” (Exodus 22:4), with regard to livestock, yes, the primary category of Eating applies, but with regard to undomesticated animals, no, the primary category of Eating does not apply. Therefore, the tanna teaches us that undomesticated animals are included in the category of livestock in this regard and the owner of an undomesticated animal is liable for damage caused by his animal eating another person’s produce.