מדרש אויף ויקרא 3:11

5) (Vayikra 3:11): "And he shall smoke it": Fats (of one offering) may not be mixed with fats (of another). "the bread of a fire-offering to the L–rd": We are hereby taught that fats are called "bread."

10) (Vayikra 3:5) "and they shall smoke it," (Vayikra 3:11): "and he shall smoke" (Vayikra 3:16): "and he shall smoke them": Why the variations? "And they shall smoke it" — what is kasher, and not what is pasul; "And he shall smoke" — Fats (of one offering) may not be mixed with fats (of another); "and he shall smoke them" — all at the same time. It is written here: "a fire-offering," but not "bread"; and further (Vayikra 3:11): "bread," but not "a sweet savor"; and yet further (Vayikra 3:16): "a sweet savor," but not "to the L–rd." Whence do we derive that all of these elements apply to each instance? "fire-offering" (written in respect to each) indicates identity (for all of the elements).