On occasion, the vessel used to hold the flour for a meal offering was made in such a way that there were different compartments. The Gemara on today’s daf (=page) teaches that in such a case although the vessel holding the meal-offerings separates it, nevertheless it is considered a single, valid offering, since it is held together in a single vessel.
This ruling is true because both parts of the meal-offering were in a single vessel simultaneously. Rava asks whether we can extend this concept to other cases. What if the meal-offering was divided into two parts and one of them becametameh – ritually defiled – and was then placed in the vessel together with the other part that remained in a perfectly pure state. Simply being in close proximity in the vessel would not allow one part to defile the other. Rava’s question is what happens if a person who is ritually defiled touches the part that is already defiled. Do we say that since the two parts are together in a single vessel, then touching one part is equivalent to touching the entire meal-offering, or, perhaps, the part that is defiled is “full” of defilement and cannot be defiled further? If this latter possibility is correct, then the part that has not yet been defiled would not be affected.
Although the Gemara does not reach any clear conclusion regarding this question, the Sefat Emet asked why the Gemara chose to introduce such a basic question – whether something that is already tameh can receive further defilement – in the context of an obscure case such as this one. From the Ramban in Masechet Shevu’ot (11b) it appears that this question only applies in a case where both parts are in a single vessel, for if they were connected in other ways, e.g. if two pieces of meat were combined in a pastry wrapping, it is clear that the defilement would affect the entire thing.