"If an ox gores" (Exodus 21:28). Our Rabbis taught: "if an ox gores a man," goring is only with the horn. And so it says "and Zedekiah son of Kenaanah made for himself horns of iron and said, Thus says the LORD, with these you shall gore Aram" (1 Kings 22:11). And it says "his firstling bull, majesty is his, and his horns are the horns of a wild ox" and so forth (Deuteronomy 33:17). What is [the force of] "and it says"? In case you should say, we do not derive words of Torah from words of tradition [the Prophets and Writings], come and hear: "his firstling bull, majesty is his." But is that a derivation? It is merely the disclosure of a matter, that goring is with the horn. Rather, [the verse is needed] lest you say: when the Merciful One distinguished between an innocuous ox and a forewarned one, this applies to a detached [horn], but with an attached [horn] say it is all forewarned. Come and hear: "his firstling bull, majesty is his." What is a derivative of the horn? Shoving, biting, lying down [upon], kicking. Why is goring singled out and called a primary category, since it is written "if it gores"? Shoving too is written "if it strikes" (Exodus 21:35); that striking is goring. For it was taught: "if it strikes" Scripture opened with striking and concluded with goring, to tell you this is goring, this is striking. Why is it written regarding a man "if it gores" and regarding a beast "if it strikes"? A man, who has a guardian fortune [mazal], it is written "if it gores"; a beast, which has no guardian fortune, it is written "if it strikes." And in passing Scripture teaches us that one forewarned toward men is forewarned toward beasts, but one forewarned toward beasts is not forewarned toward men.
Goring Is Only With the Horn
Yalkut Shimoni on Torah 339:7
(שמות כא כח) כִּי יִגַּח שׁוֹר, תָּנוּ רַבָּנָן, כִּי יִגַּח שׁוֹר אִישׁ, אֵין נְגִיחָה אֶלָּא בְּקֶרֶן. וְכֵן הוּא אוֹמֵר (מלכים א כב, יא) "וַיַּעַשׂ לוֹ צִדְקִיָּה בֶן כְּנַעֲנָה קַרְנֵי בַרְזֶל וַיֹּאמֶר כֹּה אָמַר ה' בְּאֵלֶּה תְּנַגַּח אֶת אֲרָם". וְאוֹמֵר "בְּכוֹר שׁוֹרוֹ הָדָר לוֹ וְקַרְנֵי רְאֵם" וְגוֹ'. מַאי וְאוֹמֵר, וְכִי תֵימָא, דִּבְרֵי תּוֹרָה מִדִּבְרֵי קַבָּלָה לֹא יָלְפִינָן, תָּא שְׁמַע, "בְּכוֹר שׁוֹרוֹ הָדָר לוֹ". וְהַאי מֵילָף הוּא, גִּלּוּי מִלְּתָא בְּעָלְמָא הוּא דִנְגִיחָה בְּקֶרֶן הוּא. אֶלָּא מַהוּ דְתֵימָא כִּי פָּלִיג רַחֲמָנָא בֵּין תַּמָּה לְמוּעֶדֶת הַנֵי מִילֵי בִּתְלוּשָׁה אֲבָל בִּמְחֻבֶּרֶת אֵימָא כֻּלָּהּ מוּעֶדֶת הִיא. תָּא שְׁמַע, "בְּכוֹר שׁוֹרוֹ הָדָר לוֹ". תּוֹלָדָה דְּקֶרֶן מַאי הִיא, נְגִיפָה, נְשִׁיכָה, רְבִיצָה, בְּעִיטָה. מַאי שְׁנָא נְגִיחָה (דִּקְרָא) [דְקָרִי] לֵיהּ אָב, דִּכְתִיב וְכִי יִגַּח, נְגִיפָה נַמִי, כְּתִיב (להלן פסוק לה) "כִּי יִגֹּף", הַהִיא נְגִיפָה נְגִיחָה הִיא. דְּתַנְיָא "כִּי יִגֹּף", פָּתַח הַכָּתוּב בִּנְגִיפָה וְסִיֵּם בִּנְגִיחָה לוֹמַר לְךָ זוֹ הִיא נְגִיחָה זוֹ הִיא נְגִיפָה. (מַה) [מַאי] שְׁנָא גַּבֵּי אָדָם דִּכְתִיב כִּי יִגַּח, וּמַאי שְׁנָא גַּבֵּי בְּהֵמָה דִּכְתִיב "כִּי יִגֹּף". אָדָם דְּאִית לֵיהּ מַזָּלָא כְּתִיב כִּי יִגַּח, בְּהֵמָה דְּלֵית לָהּ מַזָּלָא כְּתִיב "כִּי יִגֹּף". וּמִלְּתָא אַגַּב אוֹרְחָא קָא מַשְׁמַע לָן, דְּמוּעָד לְאָדָם מוּעָד לִבְהֵמָה, מוּעָד לִבְהֵמָה לָא הֲוֵי מוּעָד לְאָדָם.