Rashi on Leviticus 4:8/רש"י על ויקרא ד׳:ח׳

1ואת כל חלב פר [AND HE SHALL TAKE UP …] ALL THE FAT OF THE BULLOCK — It ought to have said “its fat” (since the פר has just been mentioned); why does it state expressly “the fat of a bullock [of a sin-offering]” (i.e. any bullock brought as a sin-offering)? In order to include also the bullock of the Day of Atonement in respect to the burning of the kidneys, the fat portions and the lobe (Sifra, Vayikra Dibbura d'Chovah, Chapter 4 1).

2החטאת — [THE FAT OF THE BULLOCK OF] THE SIN OFFERING (implying, the fat of the bullock because it is a sin-offering) consequently serves to include the goats brought as a sin-offering for idolatry (Numbers 15:24) in respect to the burning of the kidneys, the fat portions and the lobe of the liver (Sifra, Vayikra Dibbura d'Chovah, Chapter 4 1; cf. Note on the previous passage).

3ירים ממנו AND HE SHALL TAKE FROM IT [ALL THE FAT] — from. “it”, i. e. from the bullock — consequently he must take it (the fat) whilst it is still connected with it (the animal), — that he must not dismember it before removing the fat from it. Thus is it explained in Torath Cohanim (Sifra, Vayikra Dibbura d'Chovah, Chapter 4 1).