imparted by treading, e.g., if a man who experiences a gonorrhea-like discharge [zav] lay down on it and transferred to it this severe impurity, and afterward one made a curtain [villon] of it, it is pure with regard to ritual impurity imparted by treading, as it is no longer fit for sitting or lying down. But it is impure due to having been in contact with an item that became ritually impure with impurity imparted by treading, as it is viewed as having been in contact with itself, and therefore it can impart impurity to food and drink.

The mishna continues: Rabbi Yosei said: What source of impurity imparted by treading did this curtain touch? Rather, the halakha is that if a zav touched the sheet itself before it was made into a curtain, and did not only lie on it without touching it directly, then although the curtain is pure with regard to ritual impurity imparted by treading, it is nevertheless impure due to contact with a zav. This is because the impurity transmitted by contact with a zav applies in the case of a curtain, which is not the halakha with regard to impurity imparted by treading.

Abaye comments: When a zav touched the sheet, in any event it was rendered impure, even if he touched it after he lay on the sheet, thereby rendering it impure with impurity imparted by treading. In this manner, it was rendered impure with the ritual impurity imparted by treading, and afterward it was again rendered impure due to contact with a zav. According to the statement of Rava, why would this be the halakha? Let us say that the item is already saturated with impurity and cannot be rendered impure a second time.

Rava said to him in response: And from where do you know that this statement of Rabbi Yosei: That if a zav touched the sheet it is nevertheless impure due to contact with a zav, is referring to a case where a zav touched the sheet after it was rendered impure with the ritual impurity imparted by treading? Perhaps he was referring to a case where a zav touched the sheet, rendering it impure due to contact with a zav, before he lay on it and rendered it impure with the ritual impurity imparted by treading. In that case, the severe form of ritual impurity imparted by the treading of the zav, which is a primary source of ritual impurity that imparts impurity to all people and items, takes effect in addition to the lesser form of impurity imparted by contact with a zav, which imparts impurity only to food and drink.

But here, in the case of part of a meal offering that was touched by one who immersed that day after having already become impure due to the touch of one who immersed that day, where both this and that are lesser forms of impurity, perhaps the impurity does not take effect a second time, as it is already impure.

The Gemara suggests: Rather, the proof against the existence of a principle that an item can be saturated with impurity and not susceptible to becoming impure a second time is from the last clause of a baraita that corresponds to the mishna: Rabbi Yosei concedes that in a case of two sheets that are folded and placed on top of one another, and a zav sat upon them, the top sheet is rendered impure with the ritual impurity imparted by treading, and the bottom sheet is rendered impure with the ritual impurity imparted by treading and due to contact with the top sheet that has become ritually impure with impurity imparted by treading. The Gemara explains: But according to the opinion advanced in Rava’s dilemma, why would this be the case? Let us say that the bottom sheet is already saturated with impurity and cannot be rendered impure a second time.

The Gemara rejects this proof: There, with regard to the bottom sheet, the two types of impurity take effect simultaneously, whereas here, with regard to the impure meal offering, the two forms of impurity take effect one after the other. It is only in the latter case that Rava suggests that the second type of impurity does not take effect. Therefore, there is no conclusive proof, and the question raised by Rava remains unresolved.

§ Rava says: In a case where one divided a tenth of an ephah of a meal offering into two halves, and one half was lost and he separated another half in its stead, and afterward the first lost half was found, and all three are placed in a receptacle together, if the one that had been lost became impure, the previously lost half-tenth of an ephah and the first half-tenth of an ephah join together and become impure, in accordance with the mishna cited earlier (Ḥagiga 20b) that a vessel joins the two together with regard to ritual impurity. But the half-tenth of an ephah that was separated to replace the lost half-tenth does not join together with the other half-tenths, and it remains pure.

If the one that had been separated to replace the lost half-tenth became impure, then the separated half-tenth and the first half-tenth join together and become impure, since the former was separated in order to complete the tenth together with the first half-tenth, while the previously lost half-tenth does not join together with them. If the first half-tenth became impure, then both the previously lost half-tenth as well as the half-tenth that was separated as its replacement join together and become ritually impure, as each of them had at one point been part of the same tenth as the first half-tenth.

Abaye says: Even if any one of the half-tenths became impure, both remaining half-tenths join together and become impure as well. What is the reason? They are all residents of one cabin, i.e., they were meant to be part of the same meal offering.

And similarly, according to Rava, with regard to the removal of the handful, if one removed the handful from the previously lost half-tenth, its remainder and the remainder of the first half-tenth of an ephah are eaten by the priests, while the half-tenth of an ephah that was separated in its stead is not eaten. Since it was not meant to join together with this other half-tenth, the removal of the handful does not permit its consumption. If one removed the handful from the one that had been separated in place of the lost half-tenth, then its remainder and the first half-tenth of an ephah are eaten, while the previously lost half-tenth is not eaten.

If one removed the handful from the first half-tenth, then both the previously lost half-tenth as well as the half-tenth that had been separated in its stead are not eaten. This is because the removal of the handful allows the remainder of only one tenth to be eaten, and it is not known whether the consumption of the previously lost half-tenth or the replacement half-tenth has now been permitted.

Abaye says: Even if one removed the handful from any one of them, both remaining half-tenths are not eaten. What is the reason? They are all residents of one cabin, and it is not possible to know whether the consumption of one or of the other has been permitted.

Rav Pappa objects to this ruling of Abaye: And is that to say that in any event the remainder of the half-tenth itself from which the handful was taken is eaten? But one-sixth [danka] of the handful that was removed was not sacrificed to permit this remainder. The handful was removed to permit the consumption of the remainders of all three half-tenths of an ephah in the receptacle. Since the handful included one-third that was removed to account for the half-tenth that is not needed, it turns out that each of the two actual half-tenths should have had an additional one-sixth removed to render them permitted.

Rav Yitzḥak, son of Rav Mesharshiyya, also objects to this ruling of Abaye: And with regard to the handful itself, how can it be sacrificed? But one-third of it, i.e., the portion separated to permit the extraneous half-tenth of an ephah, is non-sacred.

Rav Ashi said: These questions present no difficulty, since with regard to the removal of the handful, the matter is dependent on the intention of the priest. And when the priest removes the handful, he removes it to permit the remainder of the tenth of an ephah, and not the remainder of the extraneous half-tenth. Still, the other two halves may not be eaten because it is not possible to know whether the consumption of one or of the other has been permitted.