Bava Kamma 38 - The Ox of One's Fellow

If the ox of a Jew gored an ox of the Temple treasury, or if an ox of the Temple treasury gored the ox of a Jew, the owner is exempt: “...ox of his fellow...” - and not an ox of the Temple treasury.

If the ox of a Jew gored the ox of a Canaanite, the Jew is exempt, but if the ox of a Canaanite gored the ox of a Jew, the Canaanite pays full damages – a penalty on Canaanites who had no court system and were generally not careful about other people's possessions (Meiri), thus not applicable today.