Midrasch zu Wajikra 17:6

7) (Vayikra 17:6) ("And the Cohein shall sprinkle the blood on the altar of the L–rd at the door of the tent of meeting, and he shall cause the fat to smoke, a sweet savor to the L–rd.") "And the Cohein shall sprinkle the blood on the altar of the L–rd": There is sprinkling of blood by a Cohein on the altar and there is no sprinkling of blood by a Cohein on a bamah, but even proselytes, women, and bondsmen are kasher for (officiating at) a bamah. "on the altar of the L–rd at the door of the tent of meeting": There was no "altar of the L–rd" on a bamah, but even if he sacrificed on a rock or a stone it was valid. These are the words of R. Meir. R. Shimon says: It was not valid unless he built a kind of altar and sacrificed thereon. "and he shall cause the fat to smoke, a sweet savor to the L–rd.": There is no "sweet savor" on a bamah.