for example, the halakha of the prohibition against engaging in intercourse with one’s daughter born from the victim of his rape.

As Rava says: Rav Yitzḥak bar Avudimi said to me: This prohibition is derived by means of a verbal analogy between the word henna, in the verse: ''The nakedness of your son’s daughter, or of your daughter’s daughter, even their nakedness you shall not uncover; for theirs [henna] is your own nakedness'' (Leviticus 18:10), and the word henna in a different verse: ''You shall not uncover the nakedness of a woman and her daughter; you shall not take her son’s daughter, or her daughter’s daughter, to uncover her nakedness: They [henna] are near kinswomen; it is lewdness'' (Leviticus 18:17). This verbal analogy indicates that just as intercourse with one’s granddaughter and with one’s wife’s daughter or granddaughter is forbidden, so too, intercourse with one’s daughter is prohibited.

Furthermore, it is derived from a verbal analogy between the word ''lewdness'' (Leviticus 18:17) and the word ''lewdness'' in the verse: ''And if a man take with his wife also her mother, it is lewdness; they shall be burned with fire, both he and they, so that there be no lewdness among you'' (Leviticus 20:14), that one who engages in sexual intercourse with his daughter or granddaughter is liable to be executed by burning.

''Between blood and blood''; this is the ability to discern between the disparate halakhot relevant to the blood of menstruation, the blood of childbirth, and the blood of a gonorrhea-like discharge [ziva]. In each of these cases, there is a dispute between the Sages with regard to a matter for whose intentional violation one is liable to receive karet. In the case of the blood of menstruation, it is with regard to the issue that is the subject of the dispute between Akavya ben Mahalalel and the Rabbis, as we learned in a mishna (Nidda 19a): With regard to blood that is green that is discharged by a woman, Akavya ben Mahalalel deems it blood of menstruation and impure, and the Rabbis deem it pure. According to Akavya ben Mahalalel, one who engages in intercourse with a woman who discharged green blood is liable to receive karet, while according to the Rabbis, he is exempt.

In the case of the blood of childbirth, the dispute concerning such a prohibition is with regard to the issue that is the subject of the dispute between Rav and Levi. This is as it was stated that Rav says: Blood that a woman discharges after childbirth is all from one source; the Torah deemed ritually impure the blood discharged for one week after the birth of a male and two weeks after the birth of a female, and the Torah deemed ritually pure the blood that is discharged for the subsequent thirty-three days for a male and sixty-six days for a female. Even if the blood flows continuously, the status of the blood changes after the conclusion of the period of impurity.

And Levi says: It is from two sources; the impure source is sealed after one week for a male and two weeks for a female, and then the pure source is opened, and at the conclusion of the period of the discharge of pure blood, the pure source is sealed and the impure source is opened. Only if the flow of impure blood ceases is a subsequent discharge deemed pure. Therefore, if one engaged in intercourse with a woman who experienced a continuous flow of blood beyond the time of the conclusion of the period of the flow of pure blood, according to Levi, he is liable to receive karet, and according to Rav, he is exempt.

In the case of the blood of ziva, the dispute concerning such a prohibition is with regard to the issue that is the subject of the dispute between Rabbi Eliezer and Rabbi Yehoshua. As we learned in a mishna (Nidda 36b): In a case where a woman experienced labor pain accompanied by an emission of blood lasting three consecutive days within the eleven days between the periods when her emissions render her a menstruating woman, during which the emission of blood renders the woman a zava, if she ceased experiencing labor for a twenty-four-hour period, indicating that the blood was not the result of imminent birth, and then she gave birth, that woman gives birth as a zava and is liable to bring the purification offerings of both a woman after childbirth and a zava; this is the statement of Rabbi Eliezer.

The mishna continues: And Rabbi Yehoshua says: That is her status only if she ceased experiencing labor for a twenty-four-hour period that is a night and the day that follows, like Shabbat evening and the day that follows it. When the mishna says that she ceased, it is referring to a case where she ceased from having labor pains and not from having the flow of blood. The dispute is whether the woman who gave birth has the status of a zava, who is required to count seven clean days before immersing in flowing water, or whether she has the status of a woman after childbirth. If the two weeks of the blood of impurity after childbirth elapsed and she did not immerse in flowing water, according to Rabbi Eliezer, she remains a zava, and one who engages in intercourse with her is liable to receive karet. According to Rabbi Yehoshua, at that point the blood becomes the blood of purity, and one who engages in intercourse with her is not liable to receive karet.

''Between plea and plea''; this is the ability to discern between cases of capital law, cases of monetary law, and cases of laws involving lashes. The Gemara elaborates: In cases of monetary law, the dispute concerning such a prohibition is with regard to the issue that is the subject of the dispute between Shmuel and Rabbi Abbahu, as Shmuel says: With regard to two judges who sat in judgment and issued a ruling in cases of monetary law, their ruling is a valid ruling, but they are characterized as an impudent court. And Rabbi Abbahu says: Everyone agrees that their ruling is not a valid ruling. If a tribunal of two judges rules that one of the litigants must pay the other money, and that litigant uses the money to betroth a woman, according to Shmuel she is betrothed, and one who intentionally engages in intercourse with her is liable to receive karet. According to Rabbi Abbahu she is not betrothed, and one who engages in intercourse with her is not liable.

In cases of capital law, the dispute concerning such a prohibition is with regard to the issue that is the subject of the dispute between Rabbi Yehuda HaNasi and the Rabbis, as it is taught in a baraita that Rabbi Yehuda HaNasi says with regard to that which is written: ''If men struggle and they hurt a pregnant woman…and if there shall be a tragedy you shall give a life for a life'' (Exodus 21:22–23), the reference is to a monetary payment for the life that he took. The tragedy referenced is the unintentional killing of the mother.

The tanna deliberates: Do you say that the reference is to a monetary payment, or perhaps the reference is only to giving his actual life? Based on the language employed in the verse, it can be determined that the reference is to monetary payment. In these verses, giving is stated above: ''And you shall give a life for a life,'' and giving is stated below: ''He shall be punished, as the husband of the woman shall impose upon him, and he shall give as the judges determine'' (Exodus 21:23). Just as there, in the phrase ''Give as the judges determine,'' the reference is to monetary payment, so too here, in the phrase ''Give a life for a life,'' the reference is to monetary payment. The Rabbis hold that the reference is to giving his actual life. If an heir of the victim betrothed a woman with money seized from the assailant, according to Rabbi Yehuda HaNasi the woman is betrothed, while according to the Rabbis she is not betrothed.

In cases of laws involving lashes, the dispute concerning such a prohibition is with regard to the issue that is the subject of the dispute between Rabbi Yishmael and the Rabbis, as we learned in a mishna (2a): Cases concerning the violation of prohibitions that render one liable to receive lashes are adjudicated by three judges. The Sages stated in the name of Rabbi Yishmael: Cases concerning lashes are adjudicated by twenty-three judges. According to Rabbi Yishmael, if a tribunal of three sentences an individual to lashes, that individual can claim damages for any injury caused as a result of the lashes, and if he betroths a woman with that money the betrothal is valid. According to the Rabbis, he cannot claim damages, as the court is authorized to sentence him to receive lashes.

''Between mark and mark''; this is the ability to discern between the disparate halakhot relevant to leprous marks of a person, leprous marks on houses, and leprous marks on garments.

In the case of leprous marks of a person, the dispute concerning such a prohibition is with regard to the issue that is the subject of the dispute between Rabbi Yehoshua and the Rabbis, as we learned in a mishna (Nega’im 4:11): If the snow-white leprous mark [baheret] preceded the white hair, the individual is impure with leprosy, as that is the order of events that appears in the Torah, and if the white hair preceded the baheret, the individual is pure. If there is uncertainty concerning which appeared first, the Rabbis say: He is impure, and Rabbi Yehoshua says: It has darkened. The Gemara asks: What is the meaning of: It has darkened? Rava says: Its status is like that of a baheret that darkened, with regard to which the Torah says that he is pure. If one with a baheret and a white hair entered the Temple, and there is uncertainty concerning which appeared first, according to the Rabbis he is liable to receive karet, and according to Rabbi Yehoshua he is not liable.

In the case of leprous marks of houses, the dispute concerning such a prohibition is with regard to the issue that is the subject of the dispute between Rabbi Elazar, son of Rabbi Shimon, and the Rabbis, as we learned in a mishna (Nega’im 12:3): Rabbi Elazar, son of Rabbi Shimon, says: A house is never deemed impure with leprosy unless the leprous mark will be seen to be the size of two Cilician beans, on two stones, on two walls, in a corner between two walls. The length of the mark is that of two Cilician beans and its width is that of one Cilician bean.

The Gemara asks: What is the reason for the opinion of Rabbi Elazar, son of Rabbi Shimon? The Gemara answers: The word wall is written in the verse and the word walls is written in the same verse: And he shall see the leprous mark…in the walls of the house with hollow streaks, greenish or reddish, and their appearance is lower than the wall'' (Leviticus 14:37). Which is one wall that is like multiple walls? You must say: This is a corner between two walls. The Rabbis hold that it is a leprous house even if the mark appears on one wall. Therefore, one who entered a house with a leprous mark on one wall and then entered the Temple is liable to receive karet according to the Rabbis; according to Rabbi Elazar, son of Rabbi Shimon, he is not liable.

In the case of leprous marks on garments, the dispute concerning such a prohibition is with regard to the issue that is the subject of the dispute between Rabbi Yonatan ben Avtolemos and the Rabbis, as it is taught in a baraita that Rabbi Yonatan ben Avtolemos says: From where is it derived