with regard to whether to leave in abeyance, i.e., to treat as uncertain, blood the color of water in which a fenugreek plant is soaked, or the color of the liquid that drips from roast meat. According to the first tanna of the mishna there are five types of blood that are definitely impure, whereas other types, such as those mentioned by Beit Shammai, are deemed impure due to uncertainty. By contrast, Beit Hillel maintain that blood of these colors is entirely pure.

§ The mishna states: Blood that is green, Akavya ben Mahalalel deems it impure. The Gemara asks: But does Akavya ben Mahalalel not accept the exposition of Rabbi Abbahu that the two verses: “Dameha” (Leviticus 12:7), and: “Dameha” (Leviticus 20:18), indicate that there are four types of blood here?

The Gemara answers: If you wish, say that Akavya ben Mahalalel does not accept this opinion of Rabbi Abbahu, as he maintains that there are more than four types of blood in a woman. And if you wish, say instead that Akavya ben Mahalalel accepts Rabbi Abbahu’s exposition, and the apparent contradiction can be resolved as follows: Didn’t Rabbi Ḥanina say, with regard to the black blood mentioned in the mishna, that it is actually red but its color has faded? Here too, with regard to the green mentioned by Akavya ben Mahalalel, one can say that it was initially red but its color faded and turned green.

§ The mishna states with regard to blood that is green: And the Rabbis deem it pure. The Gemara asks: Isn’t this opinion of the Rabbis identical to the opinion of the first tanna? The Gemara answers: There is a practical difference between them with regard to whether to leave in abeyance blood that is green. According to the first tanna of the mishna there are five types of blood that are definitely impure, whereas other types, such as green, are impure due to uncertainty. By contrast, the Rabbis maintain that green blood is entirely pure.

§ The mishna states that Rabbi Meir said: Even if the green blood does not transmit impurity due to the halakhot of a blood stain or the blood of a menstruating woman, it is blood in that it renders food susceptible to ritual impurity due to its status as one of the seven liquids that render food susceptible.

Rabbi Yoḥanan says: Rabbi Meir accepted the opinion of Akavya ben Mahalalel and deemed green blood impure as blood of a menstruating woman. And as for his statement in the mishna, this is what Rabbi Meir was saying to the Rabbis: Granted that in a case where a woman finds a green stain on an article of clothing you do not deem her ritually impure, as its greenness is an indication that it did not come from her body. But in a case where she actually sees green blood come from her body, she shall be impure.

The Gemara raises a difficulty with this interpretation: If so, why did Rabbi Meir say: Even if it does not transmit impurity due to the halakhot of a blood stain, it renders food susceptible to ritual impurity due to its status as a liquid? According to the above explanation, he should have said: If the woman saw the emission of this blood, she is impure as a menstruating woman.

Rather, this is what Rabbi Meir was saying to the Rabbis: Granted that in a case where the woman sees green blood from the outset you do not deem her ritually impure, but in a case where she sees red blood and then sees green blood, she shall be impure. This is just as it is with regard to the halakha of the fluids of a man who experiences a gonorrhea-like discharge [zav] and a woman who experiences a discharge of uterine blood after her menstrual period [zava]. All fluids emitted by a zav or zava, such as saliva and urine, are impure. Likewise, green blood that is emitted by this woman who has already emitted red blood should be impure.

The Gemara asks: And how would the Rabbis respond to this? The Gemara answers: They maintain that the impure fluids of a menstruating woman are only those that are similar to saliva: Just as when saliva leaves one’s mouth it is first gathered together and then expelled from the body, so too, all impure fluids are those that are gathered together and then expelled. This definition serves to exclude this green blood, which is not gathered together and expelled. The Gemara asks: If so, the Rabbis spoke well to Rabbi Meir, i.e., their answer is convincing. Why does Rabbi Meir deem green blood impure?

Rather, this is what Rabbi Meir was saying to the Rabbis: Let green blood be at least like one of the seven liquids that render seeds upon which they fall susceptible to ritual impurity. Why is green blood deemed pure even with regard to this matter? And the Rabbis disagree because they require that every type of blood that renders food susceptible to ritual impurity be like that mentioned in the verse: “And drink the blood of the slain” (Numbers 23:24), i.e., the blood that flows at the time of death; and green blood is not the type that flows at the time of death. Therefore, it does not render food susceptible to ritual impurity. The Gemara again asks: If so, the Rabbis spoke well to Rabbi Meir. Why does he disagree with them?

Rather, this is what Rabbi Meir was saying to the Rabbis: Learn this halakha that green blood renders food susceptible to ritual impurity from the following verbal analogy: It is written here, in a description of the beloved woman that alludes to her menstrual blood: “Your shoots [shelaḥayikh] are an orchard of pomegranates” (Song of Songs 4:13), and it is written there: “Who gives rain upon the earth, and sends [veshole’aḥ] waters upon the fields” (Job 5:10). This verbal analogy indicates that menstrual blood is similar to water in that both render food susceptible to ritual impurity.

And the Rabbis disagree with Rabbi Meir, as they do not have a tradition that this is an accepted verbal analogy, and there is a principle that although a person may derive an a fortiori inference on his own, i.e., even though he was not taught that particular logical argument by his teachers, a person may not derive a verbal analogy on his own, but only if he received it by tradition.

§ The mishna states that Rabbi Yosei says: Neither in this sense, as the blood of a menstruating woman according to Akavya ben Mahalalel, nor in that sense, as a liquid that renders food susceptible according to Rabbi Meir, is green blood considered blood. The Gemara raises a difficulty: Isn’t this the same as the opinion of the first tanna? The Gemara answers that this is what the mishna is teaching us: Who is the first tanna? Rabbi Yosei. And the reason Rabbi Yosei’s name is mentioned is due to the principle that anyone who reports a statement in the name of the one who said it brings redemption to the world.

§ The mishna states: What is the red color of blood that is impure? It is as red as the blood that flows from a wound. The Gemara asks: What is the meaning of the phrase: As the blood that flows from a wound? Rav Yehuda says that Shmuel says: Like the blood of a slaughtered ox.

The Gemara inquires: But if so, let the tanna of the mishna say explicitly that it is as red as the blood of slaughter. The Gemara explains: If the tanna had said that it is as red as the blood of slaughter, I would say that it means as red as the blood that flows throughout the entire slaughter, and it would apply to the shades of all blood emitted during the process. Therefore, the tanna teaches us that it is as red as the blood that flows from a wound, i.e., as the blood that flows at the beginning of the slitting with the slaughtering knife.

The Gemara cites other definitions of the color described in the mishna as: Red as the blood that flows from a wound. Ulla says: It is red like the blood that flows from a living bird that was wounded. A dilemma was raised before the Sages: When Ulla specified that the bird is living, did he mean that it was not dead, to exclude the blood of a slaughtered bird? Or perhaps he meant that the bird was healthy, to exclude the blood of a weak bird. No answer was found, and therefore the Gemara concludes that the dilemma shall stand unresolved.

The Gemara cites another definition: Ze’eiri says that Rabbi Ḥanina says: It is red like the blood that comes from a squashed head louse. The Gemara raises an objection from a mishna that discusses a stain found on a woman’s garment (58b): If a woman killed a louse and subsequently found a blood stain on her garment or body, this woman may attribute the stain to that louse, and she remains pure. The Gemara explains the objection: What, is it not correct to say that this is referring to a louse from all parts of her body, not just the head, as claimed by Rabbi Ḥanina? If so, the color of impure blood is like the color of the blood of a louse from anywhere on the body. The Gemara answers: No; this halakha is referring specifically to a louse that was on her head.

The Gemara cites yet another definition of the color described in the mishna as: Red as the blood that flows from a wound. The Sage Ami of Vardina says that Rabbi Abbahu says: It is red as the blood that flows from the smallest finger of the hand, which was wounded and later healed and was subsequently wounded again. And this is not referring to the finger of any person, but specifically to the finger of a young man who has not yet married a woman. And furthermore, this does not mean any young man; rather, until what age must he be? Until twenty years old.

The Gemara raises an objection from the aforementioned mishna (58b): If the woman’s husband or son suffered an injury, she may attribute a blood stain she finds on her garment to her son or to her husband, and she remains pure. The Gemara analyzes this halakha: Granted, with regard to the ruling that she may attribute it to her son, you can find a case where this meets all the requirements specified by Rabbi Abbahu, i.e., he could be younger than twenty and unmarried. But with regard to the ruling that she may attribute it to her husband, how can you find a case where her husband is unmarried?

Rav Naḥman bar Yitzḥak says: It is possible in a case where this woman entered the marriage canopy but has not yet engaged in intercourse with her husband. In such a situation, although he is her husband he is physically akin to an unmarried young man. Therefore, she can attribute the blood stain to his wound.

Rav Naḥman says: This red is like the blood spilled in the process of bloodletting. The Gemara raises an objection from a baraita: An incident occurred involving a blood stain found on a woman’s garment, and Rabbi Meir attributed