The Gemara asks: But let him render the leaven null and void during the sixth hour, when he burns it. The Gemara answers: Since there is a rabbinic prohibition that takes effect on the leaven, as it is prohibited to derive benefit from it after the fifth hour, its legal status is like that of leaven prohibited by Torah law, and therefore it is not in his possession and he is unable to nullify it.

The Gemara continues: There is proof that the Sages were stringent with regard to leaven prohibited by rabbinic law, as Rav Giddel said that Rabbi Ḥiyya bar Yosef said that Rav said: With regard to a man who betroths a woman on the fourteenth of Nisan from the beginning of the sixth hour and onward, even if he does so with wheat from the mountains [kurdanaita], which is particularly hard and there is no certainty that it will ferment even if water falls on it, nevertheless, as it is possible that the wheat leavened, its legal status is that of leaven. Consequently, it is prohibited to derive benefit from this wheat, which is legally worthless. Therefore, if a man gives the wheat to a woman for the purpose of betrothal, one need not be concerned that it is a betrothal. The reason is that a betrothal is effective only if the man gives the woman an object worth at least a peruta. In this case the Sages disqualify the betrothal and allow the woman to marry another man, despite the fact that by Torah law she is betrothed to the first man, as the leaven with which he betrothed her is prohibited only by rabbinic law.

The Gemara raises a difficulty: And is it indeed the case that after the leaven has become prohibited one is unable to render it null and void? But wasn’t it taught in a baraita: If one was sitting in the study hall and he remembered that there is leavened bread in his house, he should render it null and void in his heart, both on Shabbat and on the Festival? The Gemara analyzes this statement: Granted, on Shabbat you can find this case, as one can nullify the leaven before it becomes prohibited, in a case where the fourteenth of Nisan occurs on Shabbat and he remembers to nullify the leaven before the prohibition takes effect. However, if he remembered on the Festival itself, it is after the prohibition has taken effect, as the Festival has already begun, and yet the baraita says that one may render the leaven null and void.

Rav Aḥa bar Ya’akov said: Here we are dealing with a student sitting before his teacher, and he remembers that there is kneaded dough in his house, and he is afraid lest it leaven before he can return home to warn the members of his household. Since the dough has not yet leavened and is not yet prohibited, he can take earlier action and render it null and void before it becomes leavened.

The Gemara comments: The language of the baraita is also precise in accordance with this explanation, as the baraita teaches: If one was sitting in the study hall. This indicates that the dough has not yet risen, and the problem is that he cannot arrive home in time to prevent it from rising. However, if it had already become leavened, rendering it null and void will not remedy the situation even if he were home. The Gemara concludes: Indeed, learn from this proof that Rav Aḥa bar Ya’akov’s interpretation is correct.

Rabba bar Rav Huna said that Rav said: With regard to a vessel that contains several loaves in which there was bread that became moldy, and it is not evident whether it is leaven or matza, once there was more matza than leaven in the vessel, it is permitted. The Gemara first analyzes the case itself: What are the circumstances? If you say that he knows that this loaf is leavened bread, even if there were more matza, what of it? What difference does it make that most of the food is matza, if it is clear that this loaf is leaven?

Rather, Rav must be speaking of a case where we do not know whether it is leavened bread or whether it is matza. However, in that case, why discuss specifically a situation where there was more matza in the vessel? Even in a case where there was not more matza in the vessel as well, the questionable loaf is likely to be matza, as let us follow the last item placed in the vessel, which even on the first day of Passover would be matza.

Didn’t we learn in a mishna: With regard to coins that were found before animal merchants in Jerusalem, they are always assumed to be money of the second tithe, as most of the animals purchased in Jerusalem were bought with that money. This halakha applies both during a Festival and throughout the year, as people would purchase animals for meat with their second-tithe money, and it can therefore be assumed that these coins have the status of second tithe. However, if the money was found on the Temple Mount it is non-sacred money, even during a Festival. It can be assumed that one who enters the Temple Mount has already purchased all the animals that he required beforehand. Any coins in his possession are non-sacred money, not tithes.

If the money was found elsewhere in Jerusalem during the Festival, when many people came to Jerusalem with their second-tithe money, the coins are presumed to be second-tithe money. However, if the coins were found during the rest of the year, it is non-sacred money.

The Gemara explains the proof. And Rav Shemaya bar Zeira said: What is the reason that during the rest of the year the coins are considered non-sacred money, even on the day after the Festival? Since the markets of Jerusalem tend to be cleaned every day, any money left there would already have been found by the street cleaners. Consequently, any coins found there were left there recently. Apparently, we say that the first ones are gone and these objects are later ones. Here too, with regard to moldy bread, let us say: The first ones have been eaten and are gone, and this food is from now and is undoubtedly matza.

The Gemara rejects this proof: It is different here, as the mold proves about the loaf that it is leaven, as food does not become moldy unless it has been sitting for a long time. The Gemara retorts: If its mold proves about the loaf that it is leaven, if there was more matza in the vessel, what of it? Even in that case, the very fact that it is moldy proves that it is leaven. Rabba said: Do not say there was more matza than leaven in the vessel; rather, say that several days of eating matza have passed over the vessel. In other words, several days of the Festival, during which matza is consumed, have passed. Therefore, it is more likely that the moldy loaf is matza.

The Gemara asks: If so, it is obvious that the moldy loaf is matza, not leaven. The Gemara answers: No, it is necessary to teach this halakha with regard to a situation where its mold is extensive. Lest you say: Since its mold is extensive the matter is revealed that it is certainly leavened bread, therefore Rav teaches us that one cannot be entirely sure that this is the case.

The Gemara explains the reason for the uncertainty. Since several days of eating matza have passed over the vessel, we say: Each and every day he baked warm loaves, which he placed upon the previous days’ matza, causing it to grow moldier. Therefore, it is possible that even though only a brief time has passed, the matza has grown very moldy, due to the moisture and heat inside the vessel.

In regard to the aforementioned principle, the Gemara asks: And do we, in general, follow the last item in determining the identity of the item in question? But wasn’t it taught in a baraita that Rabbi Yosei bar Yehuda says: With regard to a box that people used for both non-sacred coins and second-tithe coins, if the majority of its use was for non-sacred money, the coins are considered non-sacred. If the majority of its use was for second-tithe coins, the coins are considered second-tithe money. The Gemara asks: But why is this so? Let us follow the last item placed in the box.

Rav Naḥman bar Yitzḥak said: With what are we dealing here? We are dealing with a case where people used the box for both non-sacred coins and second-tithe coins, and he does not know which of the two kinds of money was placed there last.
Rav Zevid said: The baraita is referring to a case where he used one part of the box for piles of non-sacred coins and another part of the box for piles of second-tithe coins. In this case, there was no definitive most recent use of the box, as a coin may have moved from one side of the box to the other.
Rav Pappa said: We are dealing with a case where the coin was found in a hole in the box. The concern is that this coin might not be of the type last placed into the box. Instead, it is possible that this coin remained from a previous use and was not removed because it was obscured in the hole.

Rav Yehuda said: One who searches for leaven must recite a blessing. The Gemara asks: What blessing does he recite, i.e., what is the correct formula of the blessing? Rav Pappi said in the name of Rava that one recites: Who has made us holy through His mitzvot and has commanded us to remove leavened bread. Rav Pappa said in the name of Rava: One should recite: Concerning the removal of leavened bread. The Gemara comments: With regard to the formula: To remove, everyone agrees that it certainly refers to the future. This formulation undoubtedly indicates that the person reciting the blessing is about to begin fulfilling the mitzva of removing leaven, and it is therefore an appropriate blessing.