Charles Ellicott Commentary Exodus 21:28

"And if an ox gore a man or a woman to death, the ox shall be surely stoned, and its flesh shall not be eaten; but the owner of the ox shall be quit." — Exodus 21:28 (ASV)

The ox shall be surely stoned — i.e., it shall die the death of a murderer.

His flesh shall not be eaten. — An ox killed by stoning would not be bled in the usual way, and would be “unclean” food for Hebrews. According to the Rabbis, the flesh might not even be disposed of to the Gentiles, but had to be buried. If this were so, the object must have been to mark strongly that whatever creature took human life was accursed.