Rashi on Leviticus 7:33/רש"י על ויקרא ז׳:ל״ג

1‎'וגו‎‎‎‎‎‎‎‏‎ השלמים ‎ ‏‏‎דם‎ ‎את ‎‎המקריב‎ [HE AMONG THE SONS OF AARON] THAT OFFERETH THE BLOOD OF THE PEACE-OFFERINGS [AND THE FAT SHALL HAVE THE SHOULDER OF THE RIGHT SIDE FOR HIS PART] — “He that offereth the blood” means: he who is fitted to perform the sprinkling of it and to burn the fat portions, — thus excluding a priest who was unclean at the time when the blood was sprinkled, or the fat portions were burnt — that he does not share in the flesh (Sifra, Tzav, Chapter 16 8; Zevachim 98b).