damaged water cisterns in the public domain and clean them out by removing the dirt and sediment that has accumulated in them. The Gemara infers: Cleaning out the cisterns of dirt and sediment during the intermediate days of a Festival is indeed permitted, but digging a new cistern is not permitted.

Rabbi Ya’akov said that Rabbi Yoḥanan said: They taught that it is prohibited to dig new cisterns only when the public does not need them; but if the public needs them, even digging new cisterns is permitted.

The Gemara asks: And when the public needs them, is digging really permitted? But isn’t it taught in a baraita: One may clean out cisterns, ditches, and caves of an individual during the intermediate days of a Festival, and, needless to say, one may clean out those of the public. But one may not dig new cisterns, ditches, or caves of the public during the intermediate days of a Festival, and, needless to say, one may not dig those of an individual. What, is it not so that this baraita is referring to a case where the public needs them, but nevertheless digging new cisterns, ditches, and caves is prohibited?

The Gemara rejects this opinion: No, this baraita is referring to a case where the public does not need them.

The Gemara raises a difficulty: It would follow that in the corresponding situation with regard to the cisterns of an individual, the baraita is referring to a case where the individual does not need them. But in that case, is cleaning them out really permitted? Isn’t it taught in a baraita: One may gather water into the cisterns, ditches, and caves of an individual, but one may not clean them out or plaster their cracks; but for those of the public, one may indeed clean out and plaster their cracks? This indicates that on the intermediate days of a Festival, unneeded cisterns belonging to an individual may not even be cleaned out.

The Gemara rejects this difficulty: Rather, to what case does the first baraita refer? Is it referring to a case where the individual needs the cisterns? If so, then in the corresponding situation with regard to cisterns of the public, the baraita would be referring to a case where the public needs them. But in that case, is digging new cisterns really prohibited? Isn’t it taught in yet another baraita: One may gather water into cisterns, ditches, and caves of an individual, and one may clean them out, but one may not plaster their cracks, clear earth into them in order to fill in the cracks, or lime them with lime so that they hold water. But with regard to those of the public, one may even dig them out and lime them with lime. Therefore, in a case where the public needs them, it is permitted to dig out public cisterns.

But if so, the first baraita, which states that one may not dig new cisterns even for the public, is difficult, as it is contradicted by this last baraita. The Gemara explains: Answer the difficulty and explain the first baraita as follows: One may clean out cisterns, ditches, and caves of an individual during the intermediate days of a Festival when the individual needs them; and needless to say, one may clean out those of the public when the public needs them, as even digging new cisterns is permitted when the public needs them.

But one may not dig cisterns, ditches and caves for the public when the public does not need them. And needless to say, one may not dig them for an individual, as when an individual does not need the cisterns on the intermediate days of a Festival, even cleaning them out is prohibited. In this way all of the seemingly contradictory sources can be reconciled.

Rav Ashi said: The wording of the mishna is also precise, indicating that when there is a public need for such cisterns, they may be dug even on the intermediate days of a Festival. As it teaches: One may tend to all other public needs. What does the word all come to add that was not stated explicitly? Does it not come to add the digging of cisterns, which is permitted?

The Gemara rejects this opinion: No, the word all comes to add that which is taught in the following baraita: On the intermediate days of a Festival, agents of the court go out to clear thorns from the road, and to repair the city streets and highways [isterata’ot], and to measure the ritual baths to ascertain that they have the requisite quantity of water. And if any ritual bath does not contain forty se’a, the minimal measure for ritual purification, they direct [margilin] a stream of water into it, such that it flows over the ground before entering the bath, so as not to disqualify the water as drawn water until it holds forty se’a of water.

And from where is it derived that if agents of the court did not go out and do all these repairs, that with regard to any blood that is shed there on account of their negligence, the verse ascribes to them guilt as if they had shed it? The verse states with regard to the cities of refuge that offer protection to someone who committed inadvertent manslaughter: “That innocent blood be not shed in your land, which the Lord your God gives you for an inheritance, and so blood be upon you” (Deuteronomy 19:10). The Gemara maintains that the mishna uses the word all to allude to the cases mentioned in this baraita, and not to the digging of public cisterns.

The Gemara questions this: But these additional cases are explicitly taught in the mishna: One may repair the roads, streets, and ritual baths, and one may tend to all other public needs. What does this last phrase come to add? Does it not come to add the digging of cisterns needed by the public? The Gemara agrees: Conclude from this that the mishna means to permit the digging of new cisterns when they are needed by the public.

§ It was taught in the mishna: One may mark graves on the intermediate days of a Festival so that passersby will know to avoid them and not become ritually impure. Rabbi Shimon ben Pazi said: Where is there an allusion in the Torah to the marking of graves? The verse states: “And when they that pass through shall pass through the land, and any see a man’s bone, then shall he set up a sign by it” (Ezekiel 39:15). Ezekiel prophesies that at some future time, the Jewish people will erect signs over the strewn remains of the dead so that others will know to avoid ritual impurity.

Ravina said to Rav Ashi: Before the prophet Ezekiel came and alluded to this obligation, who said that graves must be marked? Even before the time of Ezekiel, people were careful with regard to ritual impurity. Rav Ashi responded: And according to your reasoning, that Ezekiel was introducing a new halakha, the same question can be raised with regard to this statement that Rav Ḥisda said. As Rav Ḥisda said with regard to the halakha that one who is uncircumcised or an apostate may not serve in the Temple: This matter we did not learn from the Torah of Moses our teacher, but rather, we learned it from the words of the prophet Ezekiel ben Buzi, who said of such individuals: “No stranger, uncircumcised in heart, or uncircumcised in flesh, shall enter into My Sanctuary to serve Me” (Ezekiel 44:9).

Here too, one can ask: Before Ezekiel came, who said that such individuals cannot serve in the Temple? Rather, you must say that originally they learned it as a tradition and it was an accepted halakha for generations, and then Ezekiel came and based it on a verse. Here too, with regard to the obligation to mark graves, they originally learned it as a tradition, and then Ezekiel came and based it on a verse.

Rabbi Abbahu said: An allusion to the marking of graves may be derived from here: “And the leper in whom the plague is, his clothes shall be rent, and the hair of his head shall go loose, and he shall cover his upper lip, and shall cry: Impure, impure” (Leviticus 13:45). This verse teaches that impurity cries out to the passerby and tells him: Remove yourself. The leper must inform others of his status so that they know not to come into contact with him and thereby maintain their ritual purity. So too, in our case, graves must be marked so that others will know to avoid them and prevent contracting ritual impurity. And similarly, Rabbi Uzziel, grandson of Rabbi Uzziel the Great, said: Impurity cries out to the passerby and tells him: Remove yourself.

The Gemara asks: But with regard to this verse, does it come to teach this idea? That verse is needed for that which is taught in the following baraita: “And he shall cry: Impure, impure”; this teaches that the leper must inform the public of his distress, and the public will pray for mercy on his behalf.

The Gemara answers: If it is so that the verse comes to teach only one idea, let it write: And he shall cry: Impure. What is to be derived the repetition of impure, impure? Learn from this reiteration two ideas: First, that the leper must inform the public of his pain so that others will pray on his behalf, and second, that he must warn the public to stay away so that they avoid coming into contact with him and contracting ritual impurity.

Abaye said: An allusion to the marking of graves may be learned from here, as it is written: “You shall not put a stumbling block before the blind” (Leviticus 19:14). Rav Pappa said the obligation is alluded to in the verse: “And He will say: Pave, pave, clear the way, take up the stumbling block out of the way of My people” (Isaiah 57:14), which indicates that roads must be cleared of all obstacles and hazards.

Rav Ḥinnana said: This may be derived from the end of that very same verse: “Take up the stumbling block from the way of My people” (Isaiah 57:14). Rabbi Yehoshua, son of Rav Idi, said: This may be derived from the verse: “And you shall show them the way in which they must walk” (Exodus 18:20), i.e., you must properly repair the roads, which includes marking graves.

Mar Zutra said that an allusion to this obligation is found in the verse “Thus you shall separate the children of Israel from their impurity” (Leviticus 15:31), which indicates that people must be warned to stay away from that which could cause them to become ritually impure. Rav Ashi said it is derived from the verse: “And you shall keep My charge” (Leviticus 18:30), which means that you must establish a safeguard for My charge, i.e., protective measures must be enacted to prevent people from transgressing halakha, a task that includes distancing people from ritual impurity by marking off graves, so that they not come to convey ritual impurity to teruma or other consecrated items.

And finally, Ravina said: This obligation is alluded to by the verse “And to him who orders his way, I will show the salvation of God” (Psalms 50:23), meaning that one must mark the pathways that are ritually pure and upon which it is appropriate to walk.

With regard to the verse from Psalms cited above, Rabbi Yehoshua ben Levi said: Whoever appraises his ways in this world and contemplates how to act in the most appropriate way possible merits seeing the salvation of the Holy One, Blessed be He, as it is stated: “And to him who orders his way.” Do not read it as vesam, who orders; rather, read it as vesham, and appraises. With this reading, the verse indicates that one who appraises his ways, him will I show the salvation of God.

Rabbi Yannai had a certain student who would raise difficulties with his teachings every day as they were learning. On Shabbat of a Festival, when the broader public would come to hear the lesson, the student would not raise any difficulties, lest Rabbi Yannai lack an immediate answer and suffer embarrassment.