Midrash su Levitico 7:25

2) This tells me only of the (native) children of Israel. Whence do I derive for inclusion (in the prohibition against cheilev) proselytes and freed slaves? From (Vayikra 7:25) "For all who eat cheilev." "All cheilev of ox or sheep or goat you shall not eat": This excludes (from the cheilev prohibition) unclean beasts, animals, and birds.

3) ("And he shall present …) the fat that covers the innards and all the fat that is on the innards": (This is written five times.) What is the intent of this? Because it is written (Ibid. 3:16): ("And the Cohein shall smoke …) all the fat for the L–rd. (17): … All fat and all blood you shall not eat… (Vayikra 7:25): For all who eat fat of the beast of which one presents a fire-offering to the L–rd, the soul that eats shall be cut off from its people" — I might think that even the wall-fat (the fat of the heart, the chest, and the throat) is included (in the interdict against eating fat); it is, therefore, written: "the fat that covers the innards (the entrails)." I might think that it (eating wall-fat) is not subject to the punishment (kareth), but that it is subject to the exhortation; it is, therefore, written (again): "the fat that covers the innards." would then exclude only the (wall-) fat of chullin, but not that of a consecrated animal; it is, therefore, written (again): "the fat that covers the innards" (i.e., only that fat is intended.) I might think that it (eating the wall-fat of a consecrated animal) is not subject to the punishment, but that it is subject to the exhortation; it is, therefore, written (again): "the fat that covers the innards." I might think that it is not subject to the exhortation and that it is subject to sacrifice (if he so wishes, even though he may eat it); it is, therefore, written (for the fifth time): "the fat that covers the innards" (Only that fat is to be sacrificed.)

4) This tells me only of (the prohibition of the) cheilev of full-breed oxen, sheep, or goats. Whence do I derive that of kilaim (hybrids) (of sheep and goats for inclusion in the prohibition)? From "of ox or sheep or goat." These are the words of R. Akiva. And if you wish, you can say that it is derived from (Vayikra 7:25) ("For all who eat cheilev) of the beast," including a hybrid. What is the intent of (Vayikra 7:23) "all cheilev"? I might think that only what is included in the punishment (kareth) is included in the exhortation (against eating cheilev), (but the cheilev of) a koi (an animal whose status is in doubt, i.e., is it "domesticated" [whose cheilev is forbidden] or "non-domesticated" [whose cheilev is permitted]?) or less than an olive-size (the minimum for kareth), (I might think that since they are not included in the punishment (kareth) they are not included in the exhortation (not to eat). It is, therefore, (to negate this,) written "all cheilev."