Комментарий к Дварим 25:4

לא תחסם שור THOU SHALT NOT MUZZLE THE OX [WHEN HE TREADETH OUT THE CORN] — Scripture is speaking of what usually occurs, but the same law applies to any cattle, non-domesticated beast and fowl that are doing some work that is connected with food. But if so why does it (Scripture) state “ox”? To exclude a human being from being subject to this law! (i.e. that if he restrains a workman from eating whilst engaged on some operation connected with food, the master is exempt from flagellation usually inflicted on one who transgresses a negative commandment) (Bava Metzia 88b).

לא תחסם שור בדישו, “Do not muzzle an ox while he is threshing.” The prefix ב in the word בדישו is similar to the prefix ב in the word בבאכם אל אהל מועד in Leviticus 10,9 where it means “when.” Just as in that verse the Torah does not mean literally “when you enter,” but refers to the priest having drunk wine prior to his entering the Sanctuary (and thereby being intoxicated), so here too the word בדישו means: “in anticipation of its starting to thresh.” Even if the owner muzzled the ox before it entered the threshing ground he is guilty of violating this commandment (compare Baba Metzia 90).

But this applies as well to all domesticated animals, wild animals and fowl, etc. Because we derive this by comparing the word “ox” to the word “ox,” [by means of a gezeira shava] as explained above (22:10).