Chabad.org — English translation + Rashi
Torah Temimah points to Chullin 49b.
E-Daf.com — Chullin 49b
HebrewBooks / Shas PDF
English: Rabbi Yishmael says: to include the fat on the kevah; and Rabbi Akiva says: to include the fat on the thin intestines.
Scope of chelev on the innards — debate between R. Yishmael and R. Akiva over which visceral fat is included.
There is a Tannaitic debate on which visceral fat is included in “all the fat on the innards.” Rabbi Yishmael includes the fat on the kevah; Rabbi Akiva includes the fat on the thin intestines. The dispute turns on how broadly the verse’s language extends the prohibition and the sacrificial offering of those particular deposits of fat.