The 181st prohibition is that we are forbidden from eating [meat from] an animal which is treifa.

The source of this prohibition is G‑d's statement,1 "Do not eat flesh torn off (treifa) in the field."

The simple meaning of this verse2 is as explained in the Mechilta, "The verse just speaks of the most common case, [a field being] the place where most animals are torn."

But the Oral Tradition3 has an additional explanation of this verse: "Flesh in the field is treifa, therefore do not eat it." This means that once the flesh is moved outside its proper place, it is considered to be treifa. Examples of this are meat from kodshei kodshim which was taken outside the Temple courtyard; or meat from kodshim kalim which was taken outside the wall [of Yerushalayim]; or meat from the Pesach offering which was taken away from where its group was; or if a fetus stuck its hand out [of the womb], as explained in the fourth chapter of Chulin. In all these cases the meat is called treifa, and one who eats a kezayis of their flesh receives lashes by Torah law.

Flesh which was taken from a live animal is also considered to be treifa, and one who eats it is punished by lashes. Our Sages said in Gemara Chulin,4 "The verse, 'Do not eat flesh torn off (treifa) in the field,' refers to flesh from a live animal and flesh from a treifa.

This mitzvah, as well as the previous one [regarding neveilah], is repeated with regard to kohanim. This is in G‑d's statement to the kohanim,5 "He shall not eat a neveilah or a treifa, since it will defile him." The reason for the repetition is because they are commanded to eat from a bird which was brought as a sin offering, which is prepared with melikah.6 Melikah, when performed on a non-sanctified bird is undoubtedly neveilah, not valid slaughter. We might think that therefore they are permitted to eat even non-sanctified animals prepared through melikah, as well as any other invalid slaughter. Therefore [the verse] explains that they are included among all other Jews regarding the prohibition of eating neveilah and treifa. This is the explanation given by our Sages, in addition to another law derived from this verse, which we don't need to discuss in the present work.

However, a beheimah or chaya which develops one of the invalidating conditions (treifos) which are derived through the principles of Torah interpretation may not be eaten even if it is slaughtered properly. One who slaughters it in a kosher manner and eats from its flesh receives lashes by Rabbinic decree. The various types of treifos are explained in the third chapter of Chulin. The nine7 previous mitzvos are explained in that same chapter, as well as the last chapter of Makos and the first chapter of B'choros.