Rashi on Leviticus 3:3/רש"י על ויקרא ג׳:ג׳

1‎'ואת כל החלב וגו [AND HE SHALL OFFER … ALL THE FAT THAT COVERETH THE INWARDS] AND ALL THE FAT [THAT IS UPON THE INWARDS] — These apparently redundant words are intended to include in the command the fat also that lies upon the maw. This is the opinion of Rabbi Ishmael; Rabbi Akiba holds that they are intended to include only the fat that is on the gut (Sifra, Vayikra Dibbura d'Nedavah, Section 14 6; cf. Chullin 49b).