The Torah states: "And if an ox gore a man or a woman and they die, the ox shall surely be stoned" (Exodus 21:28). The Mekhilta DeRabbi Yishmael asks: why does the Torah need this verse at all? The law about a goring ox should already be covered by an earlier, more general verse.
In (Exodus 21:12), the Torah states: "The striker of a man — if he die — shall be put to death." This is a broad principle: anyone or anything that fatally strikes a person is subject to death. An ox that gores and kills should fall under this general rule automatically.
So why does the Torah single out the ox in a separate verse? The Mekhilta explains: Scripture separated the ox from the general category in order to impose a specific severity. The general rule says "put to death" without specifying the method. By dedicating a separate passage to the ox, the Torah can specify that the ox must die by stoning — a particular and public form of execution.
Stoning is not merely death. It is a communal act, carried out with deliberation and public witness. By singling out the goring ox for this specific penalty, the Torah makes a statement about the seriousness of an animal that kills. The ox is not quietly dispatched. Its death is a public event — a visible demonstration that the taking of human life, even by an animal, demands a weighty communal response.
This is why the Torah devotes an entire section to the goring ox rather than leaving it under the general rule. The specificity of the penalty required a specific verse to establish it.