Abaye says: This is what the baraita is saying. From where is it derived to render a relative who comes from his family, e.g., the daughter of his daughter and the daughter of his son, like a relative who comes from her family, e.g., the daughter of his wife and the daughter of his wife’s daughter? Lewdness is stated here and lewdness is stated there. Just as there, the Torah renders the status of male relatives like that of female relatives, so too here, the Torah renders the status of males like that of females. The Gemara asks: But isn’t it so that with regard to a relative from his family the term lewdness is not written, as the verse states: “The nakedness of your son’s daughter, or of your daughter’s daughter, their nakedness you shall not expose; for theirs is your own nakedness” (Leviticus 18:10)?

Rava says: Rav Yitzḥak bar Avudimi said to me: The equation of his relative to her relative is derived by means of a verbal analogy between the word “henna” written with regard to his relative: “The nakedness of your son’s daughter, or of your daughter’s daughter, their nakedness you shall not expose; for theirs [henna] is your own nakedness” (Leviticus 18:10), and the word “henna” written with regard to her relative: “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). Additionally, 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 takes a woman and her mother, it is lewdness; they shall be burned with fire both him and them, and there shall be no lewdness among you” (Leviticus 20:14).

The Master says: From where is it derived to render the status of a relative below like the status of a relative above? The Gemara asks: What is the meaning of: The status of a relative below like the status of a relative above? If we say this means that the status of second-generation relative, i.e., the daughter of the son of his wife and the daughter of her daughter is like the status of first-generation relative, i.e., her daughter, this is difficult, as they are derived together, as all of them are mentioned in the same verse (see Leviticus 18:17).

Rather, it means that the status of the mother of his father-in-law and the mother of his mother-in-law is like that of his mother-in-law. The Gemara challenges: If so, is this an example of: A relative below is like the status of a relative above? On the contrary, it is an example of: A relative above is like the status of a relative below. The Gemara responds: Emend the baraita and teach: The status of a relative from the generation above is like the status of a relative from the generation below them.

The Gemara asks: If so, as for the continuation of the baraita: Lewdness is stated here, with regard to the prohibition, and lewdness is stated there, with regard to the punishment, now, if the mother of his father-in-law and the mother of his mother-in-law are not written in the Torah and are derived through interpretation, is the term lewdness written concerning them?

Abaye says: This is what the baraita is saying: From where is it derived to render the status of a relative for three generations above, his wife, his mother-in-law, and the mother of his mother-in-law, like the status of a relative for three generations below, his wife, his daughter, and the daughter of his daughter? Lewdness is stated with regard to relatives below, the offspring of his wife (Leviticus 18:17), and lewdness is stated with regard to relatives above, the ancestors of his wife (Leviticus 20:14). Just as with regard to relatives below, one is liable for engaging in intercourse with three generations of women, so too with regard to relatives above, one is liable for engaging in intercourse with three generations of women.

And just as with regard to punishment, the verse rendered the status of relatives below like that of relatives above, so too, with regard to the prohibition, the verse rendered the status of relatives above like that of relatives below.

Rav Ashi says: Actually, it is not necessary to emend the baraita, and the baraita may be interpreted as it is taught. And what is the meaning of the term below? The reference is to below in terms of the prohibition, i.e., below refers to more distant relatives, e.g., the mother of his mother-in-law, with regard to whom the prohibition is less severe, and above refers to closer relatives, e.g., his mother-in-law, with regard to whom the prohibition is more severe.

Based on that interpretation of the baraita, the Gemara asks: If so, why not say: Just as the mother of the mother of his wife is forbidden to him, so too the mother of his mother is forbidden to him, and say that he would be liable to be executed by burning?

Abaye says that it is not possible that one is liable to be burned for engaging in intercourse with the mother of his mother, as the verse states: “The nakedness of your father and the nakedness of your mother you shall not expose; she is your mother, you shall not expose her nakedness” (Leviticus 18:7). Infer from this: Due to his intercourse with his mother you deem him liable to be executed, but you do not deem him liable to be executed due to his intercourse with the mother of his mother.

Rava says: Both according to the one who says with regard to the method of derivation by means of a verbal analogy: Infer the halakha from it, i.e., from the source of the verbal analogy, and derive the details from it, i.e., from that source, and according to the one who says: Infer the halakha from it but interpret the halakha according to its own place, i.e., the derived halakha is subject to the principles that govern that which is derived by means of the verbal analogy, it is not derived that one is liable to be burned for engaging in intercourse with the mother of his mother.

The Gemara elaborates: According to the one who says: Infer the halakha from it and derive the details from it, one might infer: Just as with regard to relatives of his wife, the mother of her mother is forbidden to him, so too with regard to his relatives, the mother of his mother is forbidden to him. And derive again from it: Just as with regard to relatives of his wife, he is liable to be executed by burning due to his intercourse with the mother of her mother, so too with regard to his relatives, he is also liable to be executed by burning due to his intercourse with the mother of his mother.

The Gemara proceeds to explain why one cannot derive that one is liable to be burned for engaging in intercourse with the mother of his mother. According to the one who says: Execution by burning is more severe than execution by stoning, the inference from the halakha of relatives of his wife can be refuted as follows: What is notable about her relatives, where he is liable to be burned for engaging in intercourse with the mother of her mother? They are notable in that one who engages in intercourse with the mother of his wife is liable to be executed by the more severe punishment of burning, not the less severe, more common, punishment of stoning. Will you then say that the same halakha should apply with regard to his relatives, where one who engages in intercourse with his mother is liable to be executed by the less severe punishment of stoning?

And furthermore, as one who engages in intercourse with his mother is executed by the less severe punishment of stoning, is it possible that one who engages in intercourse with the mother of his mother, a more distant relative, is executed by the more severe punishment of burning?

And furthermore, just as with regard to her relatives, you did not distinguish between her mother and the mother of her mother, and one who engages in intercourse with either is executed by burning, so too with regard to his relatives, you should not distinguish between his mother and the mother of his mother. Since one who engages in intercourse with his mother is punished by stoning, not burning, it follows that one who engages in intercourse with the mother of his mother is punished by stoning, not burning.

And according to the one who says that stoning is more severe than burning, although the first two refutations of the derivation, based on the fact that execution by burning is more severe, are not relevant, due to this third difficulty, this halakha is not derived. Just as with regard to her relatives, you did not distinguish between her mother and the mother of her mother, so too with regard to his relatives, you should not distinguish between his mother and the mother of his mother.

And according to the one who says: Infer the halakha from it but interpret the halakha according to its own place, one might infer: Just as with regard to relatives of his wife, the mother of her mother is forbidden to him, so too with regard to his relatives, the mother of his mother is forbidden to him. And interpret the halakha according to its own place: It is there, with regard to the relatives of his wife, that one who engages in intercourse with the mother of her mother is executed by burning; but here, with regard to his relatives, one who engages in intercourse with the mother of his mother is executed by stoning, as we found that this is the punishment with regard to one who engages in intercourse with his mother.

The Gemara explains why the derivation with regard to the prohibition is not valid. According to the one who says that execution by burning is more severe than execution by stoning, the derivation can be refuted: