Menachot 57 - Why Flour Offering Should Not Leaven

Had the Torah stated only "that you offer to God shall not be prepared leaven," I would say that this applies only to the handful burned on the Altar. But since the Torah added "flour offering," this tells me that the whole offering should not be allowed to rise. And, since it also added "any flour offering," I know to apply this law to all the various flour offerings. Furthermore, since the Torah continued "That you offer to God," it tells me that one violates a prohibition only with a valid offering, but not if it became invalidated.

Rav Pappa inquired, "If a flour offering leavened, was taken outside the Courtyard, then returned, then the priest baked it and thus leavened it some more, is he liable for the second leavening?" Do we say that that he is not liable, because it has been invalidated by being taken out, or do we say that it had been invalidated by the first leavening, and then taking it out has no effect, and he is liable for the second leavening? To this there was no answer.

Art: Woman Baking Bread - Jean Francois Millet - Woman Baking Bread