Midrash su Levitico 7:23

1) (Vayikra 7:23) ("Speak to the children of Israel, saying: All fat (cheilev) of ox or sheep or goat you shall not eat.") The children of Israel are exhorted against eating cheilev, and non-Jews are not exhorted against eating cheilev. For it would follow a fortiori (that they are thus exhorted), viz.: Now if (the prohibition against (eating) ever min hechai (a limb torn from a living animal), which is not liable to kareth, obtains with the sons of Noach (non-Jews) as it does with Jews, then the prohibition against (eating) cheilev, which is liable to kareth, how much more so should it obtain with the sons of Noach as it does with Jews! It is, therefore, (to negate this,) written "the children of Israel" — The children of Israel are exhorted against cheilev, and not non-Jews.

2) (Vayikra 3:9): "its fat, the fat-tail": to include the fat near the fat-tail, the fat between the loin-sinews. These are the words of R. Akiva. R. Yehudah says: "its fat, the fat-tail": Just as (eating) fat comes under two interdicts ([Vayikra 3:17] "All fat and all blood you shall not eat," and [Vayikra 7:23] "All fat of ox or sheep or goat you shall not eat"), so, (eating the) fat of a (consecrated) fat-tail comes under two interdicts.

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.