Comentario sobre Levítico 11:46

זאת תורת הבהמה והעוף, this is the underlying motivation of the regulations governing the prohibitions affecting forbidden foods mentioned earlier.

זאת תודת הבהמה והעוף, "This is the law of the beast and of the fowl, etc." The entire verse appears superfluous. Chulin 27 explains that the reason for the verse is to teach us that birds too require ritual slaughter; we learn this from the fact that the word עוף appears between the word בהמה and the word חיה הרומשת, the fish. Placing the bird where it did, the Torah indicated it was part חיה and part דג, fish. This is why when you slaughter a bird you need to sever only either the gullet or the windpipe not both, as in the case of mammals. We now understand why the Torah (Moses) in Numbers 11,22 does not use the expression ישחט when describing the fish of the sea. We never would have expected that fish would require ritual slaughter; why did the Torah have to exclude it by writing יאסף in that verse? Answer: seeing that the Torah in our verse listed mammals, birds, and fish in one sequence, I might have thought that the common denominator is that all of them require ritual slaughter. The word יאסף in conjunction with the words: "the fish of the sea" in Numbers 11,22 ensures that we do not arrive at the conclusion that fish need to be slaughtered in the regular way. Once we know that mammals need to have two vital pipes severed by slaughter and fish none, it is easy to arrive at the conclusion that birds need to have only one vital pipe severed by slaughter.

זאת תורת הבהמה והעוף וכל נפש החיה הרומשת במים .“This is the law of the beast, and of the fowl, and of every living creature that moves on the earth. The Torah inserted the fowl between the beasts that live on the land and the creatures that inhabit the waters. It was impossible to allow the fowl to be killed regardless of certain rites to make it permissible to be eaten, but on the other hand, the Torah did not want to treat it as it had the mammals. The Rabbis therefore decided that when killing fowls ritually, only one of the vital windpipe and gullet need to be severed in order for the bird to qualify as food for Israelites. (Talmud, Chulin, folio 27.)

You may ask that if this is so why did the Torah bother to also mention נפש השורצת על הארץ "every creature that swarms on earth" i.e. the grasshoppers or locusts in our verse? Answer: The Torah was concerned that since these creatures were not mentioned as exempt from ritual slaughter by the word יאסף in connection with fish in Numbers 11,22 that I might conclude locusts have to be slaughtered. By mentioning them in our verse after the fish which do not require slaughter the Torah precludes us from making such an error.

ולכל נפש השרצות, “and for any creature that swarms upon the earth. The first letter ל in the word לכל is unnecessary, as it is in Exodus 27,3 in לכל כליו.