Reference for Bava Kamma 3:8
שְׁנֵי שְׁוָרִים תַּמִּים שֶׁחָבְלוּ זֶה אֶת זֶה, מְשַׁלְּמִים בַּמּוֹתָר חֲצִי נֶזֶק. שְׁנֵיהֶם מוּעָדִים, מְשַׁלְּמִים בַּמּוֹתָר נֶזֶק שָׁלֵם. אֶחָד תָּם וְאֶחָד מוּעָד, מוּעָד בַּתָּם מְשַׁלֵּם בַּמּוֹתָר נֶזֶק שָׁלֵם, תָּם בַּמּוּעָד מְשַׁלֵּם בַּמּוֹתָר חֲצִי נֶזֶק. וְכֵן שְׁנֵי אֲנָשִׁים שֶׁחָבְלוּ זֶה בָזֶה, מְשַׁלְּמִים בַּמּוֹתָר נֶזֶק שָׁלֵם. אָדָם בְּמוּעָד וּמוּעָד בְּאָדָם, מְשַׁלֵּם בַּמּוֹתָר נֶזֶק שָׁלֵם. אָדָם בְּתָם וְתָם בְּאָדָם, אָדָם בְּתָם מְשַׁלֵּם בַּמּוֹתָר נֶזֶק שָׁלֵם, תָּם בְּאָדָם מְשַׁלֵּם בַּמּוֹתָר חֲצִי נֶזֶק. רַבִּי עֲקִיבָא אוֹמֵר, אַף תָּם שֶׁחָבַל בְּאָדָם, מְשַׁלֵּם בַּמּוֹתָר נֶזֶק שָׁלֵם:
Two oxen, tamim, which injured each other, pay a half-nezek of the excess. [They estimate the excess of one over the other, and the one that caused the greater damage pays a half of that excess.] Both of them muadim — they pay a full nezek of the excess. One a tam; the other, a muad — the muad in the tam [i.e., if it caused greater injury to the tam than the tam to it] — it pays full nezek of the excess. The tam in the muad — it pays a half-nezek of the excess. Similarly, two men who injured each other pay a full nezek of the excess. A man in a muad, and a muad in a man — he pays a full nezek of the excess. A man in a tam, and a tam in a man — a man in a tam pays a full nezek of the excess, [a man being a muad always]; a tam in a man pays a half-nezek of the excess, [it being written (Exodus 21:31): "Or if it gore a son, or if it gore a daughter, according to this ordinance shall it be done to it." According to the ordinance of ox goring ox, so is the ordinance of ox goring man. Just as in the ordinance of ox goring ox, a tam pays a half-nezek, and a muad, a full nezek, so, in that of ox goring man, a tam pays a half-nezek, and a muad, a full nezek.] R. Akiva says: A tam, too, that injures a man pays a full nezek of the excess. [R. Akiva expounds "according to this ordinance" as referring to the law preceding this verse, that of a shor muad (an ox which is a muad), viz.: "According to this ordinance" of a shor muad, which pays a full nezek, "shall it be done to it" — to any ox that gores a man, even if it be a tam. The halachah is not in accordance with R. Akiva.]