Midrasch zu Wajikra 4:18

11) (Vayikra 4:7): "And the Cohein shall put of the blood": of the blood previously referred to (i.e., that in the receptacle and not that left over on his finger.) "on the horns of the altar": two; and later (Vayikra 4:18) it is written "horns" — four all together. These are the words of R. Shimon. R. Yehudah says (Vayikra 4:7): "which is in the tent of meeting" — to include all the corners of the tent of meeting. "the altar of the smoking (of the incense."): The (golden) altar is to be inaugurated with smoking (of the incense). "ketoreth (smoking)": It (the incense that is smoked) must come from the congregation (and not from an individual.) "samim" (incense): It must contain all of its (composite) spices, (failing which the inauguration is invalid.) "before the L–rd." What is the intent of this? R. Nechemiah said: Because we find with the Yom Kippur bullock that he stands in front of the altar (i.e., between the altar and the parocheth), and, in sprinkling, he sprinkles on the parocheth, we might think that here, too, it is so; it is, therefore, written: "the altar of the smoking of the incense before the L–rd" — (The altar is before the L–rd,) but the Cohein is not before the L–rd, (but before the altar, which is before the L–rd [i.e., before the (parocheth of the) holy of holies.])

13) Why mention again in respect to (the offering of) the congregation (Ibid. 18): "at the base of the altar of the burnt-offering"? To teach that there was no base to the inner altar itself. Why mention again in respect to the nassi (Ibid. 25): "at the base of the altar of the burnt-offering"? If the inner altar does not receive its own remnants (i.e., the blood remaining from the bullock of the high-priest, which was sprinkled on the inner altar), should it receive those of the outer altar (i.e., the remnants of the blood of the he-goat of the nassi, which was sprinkled on the outer altar)? Furthermore, is there a base to the inner altar itself? Why, then, state: "at the base of the altar of the burnt-offering"? (To teach) that (the law of pouring the remaining blood) at the base of the altar should apply to (whatever blood remains in the vessel from the offerings of) the altar of the burnt-offering. "At the base of the altar of the burnt-offering, which is at the door of the tent of meeting": the western base, (which is opposite the entrance of the heichal).