2,336. The Prohibition Against Forbidden Fats

Maachalos Assuros 7:1

If someone willfully eats an olive-sized portion of forbidden fat, he is liable to kareis (spiritual excision). If he eats it accidentally, he must bring a sin offering. The Torah tells us that one is only liable for eating the forbidden fats from the three species of kosher domesticated animals, as per Leviticus 7:23, “Do not eat any fat from an ox, a sheep or a goat.” This is so whether one eats fat from an animal that was properly slaughtered or fat from a neveila or a treifa. As far as other domesticated and wild animals, whether of kosher or non-kosher species, their fat is like their meat. Likewise, fat from a stillborn fetus of the three kosher species of animals is like its flesh; if one eats an olive-sized portion of it, he is liable to lashes for eating a neveila.

Maachalos Assuros 7:2

If someone eats forbidden fat from a neveila or a treifa, he is liable for eating fat and for eating a neveila or a treifa. Since a prohibition was added to its meat, which was permitted before the animal became a neveila or a treifa, it is also added to its fat. Accordingly, such a person would be liable to two sets of lashes.