Menahot, Chapter Five, Mishnah Four
This mishnah deals with the consequences of adding oil or frankincense to a minhah that did not require it.
1) One is liable for the oil on its own and for the frankincense on its own.
2) If he put in oil, he has rendered it invalid, but if frankincense, he can remove it.
3) If he put oil on the remainder, he has not transgressed a negative commandment.
4) If he put one vessel above the other vessel, he has not rendered it invalid.
Section one: If one adds oil and frankincense to a sinners minhah or to a minhah of jealousy, neither of which require either oil or frankincense, he has transgressed two negative commandments, for with regard to both of these the Torah specifically says not to place either oil or frankincense. Each is its own separate prohibition.
Section two: If he put oil into a minhah that does not require oil, the minhah is invalid, and there is nothing he can do to remedy it. However, if he puts frankincense in, he can simply pick out the frankincense and the minhah will remain valid.
Section three: If he put oil on the part of the minhah eaten by the priests, the remainder, then he has not transgressed the prohibition and the part offered on the altar remains valid.
Section four: If he put a vessel that has in it oil or frankincense on top of a vessel that has in it the minhah, he has not transgressed or rendered the minhah invalid because the vessels separate the substances.