פירוש על קידושין 112:12

The Talmud explains that if the words “it shall not be eaten” were the only clue we had that it should be prohibited to eat something, we would indeed say that they teach that it is prohibited to derive benefit. But in this case we know we can’t eat the stoned ox because it is nevelah (improperly slaughtered meat). Furthermore, this case is different from others because the verse says “its flesh shall not be eaten.” The extra word “flesh” intimates that its flesh is prohibited even if the animal was properly slaughtered and not stoned.