Talmud - Niddah 11a נידה י״א א׳

continuously discharging menstrual blood, their time is sufficient for all their days of pregnancy and their time is sufficient for all their days of nursing. This is the statement of Rabbi Meir. Rabbi Yosei and Rabbi Yehuda and Rabbi Shimon all say: They said that her time is sufficient only with regard to the first sighting of blood, but with regard to the second sighting, her status is like that of any other woman, and she transmits impurity for a twenty-four-hour period or from examination to examination.

§ The mishna teaches: And if she saw the first sighting as a result of unnatural circumstances, then even with regard to the second sighting her time is sufficient. Rav Huna says: If she jumped and saw menstrual blood, and again she jumped and saw menstrual blood, and a third time she jumped and saw menstrual blood, she has established a fixed menstrual cycle. The Gemara asks: For what occurrence has she established a fixed cycle? If we say that it is a cycle of days alone, this cannot be correct, as every day that she did not jump, she also did not see menstrual blood. Therefore, her cycle cannot be a mere pattern of days.

The Gemara explains: Rather, the established menstrual cycle is caused by jumps, i.e., by observing a pattern of jumping and seeing blood three times, she has established that jumping causes the onset of her menstrual period. The Gemara raises a difficulty: But isn’t it taught in a baraita: Any woman who establishes a pattern of seeing menstrual blood due to a recurring accident, even if the pattern repeats, still has not established a fixed menstrual cycle? An accidental menstrual pattern brought about by external causes does not create a menstrual cycle. The Gemara explains the difficulty: What, is it not correct to say that the baraita means that she has not established a fixed menstrual cycle at all?

The Gemara answers: No, the baraita means that she has not established a fixed menstrual cycle of days alone, nor of jumps alone, but she has established a fixed menstrual cycle for a combination of days and of jumps. In other words, she has established a fixed menstrual cycle when she jumps on specific days. The Gemara asks: Isn’t it obvious that she does not establish a cycle for days alone? Why is it necessary to state this? Rav Ashi says: It is necessary to teach this in a case where she jumped on Sunday and saw menstrual blood, and again she jumped on Sunday and saw menstrual blood, and then on the following Shabbat she jumped and did not see blood, but on Sunday, the next day, she saw menstrual blood without jumping.

Rav Ashi explains: Lest you say that the matter is revealed retroactively that it was the day that caused her to experience menstruation and not the jumping, and therefore she has established a menstrual cycle of menstruating on Sundays, regardless of jumping, the baraita teaches us that it was also the jumping of yesterday, on Shabbat, that caused the menstruation today, on Sunday. And as for the fact that she did not see menstrual blood then, that was because the time when jumping causes menstruation had not yet arrived.

The Gemara presents another version of Rav Huna’s statement. Rav Huna says: If a woman jumped and saw menstrual blood, and again she jumped and saw menstrual blood, and a third time she jumped and saw menstrual blood, she has established a fixed menstrual cycle for a pattern of days and not for a pattern of jumps. The Gemara asks: What are the circumstances? Rav Ashi says: This is referring to a case where she jumped on Sunday and saw menstrual blood, and then again she jumped on Sunday and saw menstrual blood, and then on the following Shabbat she jumped and did not see blood, but on Sunday, the next day, she saw menstrual blood without jumping. In that case there, the matter is revealed retroactively that it is the day that causes her to menstruate, not the jumping.

MISHNA: Although the Rabbis said that for a woman with a fixed menstrual cycle her time is sufficient and she does not transmit impurity retroactively, she is required to examine herself each day to ensure that she is ritually pure and will not impurify pure items that she is handling. All women must examine themselves each day except for a menstruating woman, whose impure status is known, and a woman after childbirth who is observing the period of the blood of purity, whose ritually pure status is known even if she experiences bleeding.

And even a woman with a fixed menstrual cycle engages in intercourse while using examination cloths to ascertain whether her menstrual flow began, except for a woman after childbirth who is observing the period of the blood of purity, and a virgin whose blood is ritually pure for four days after engaging in intercourse for the first time.

And she is required to examine herself twice each day: In the morning, to ascertain if she menstruated during the night, and at twilight, to ascertain if she menstruated during the day. And she is also required to examine herself at a time that she is about to engage in intercourse with her husband. The obligation of women of priestly families is greater than that of other women, as they are also required to examine themselves when they seek to partake of teruma. Rabbi Yehuda says: Even when they conclude partaking of teruma they are required to examine themselves, in order to ascertain whether they experienced bleeding while partaking of teruma.

GEMARA: The mishna teaches: All women must examine themselves each day, except for a menstruating woman. The Gemara explains: Such a woman does not need to examine herself, as during the days of her menstruation she does not need examination.

The Gemara raises a difficulty: This works out well according to the opinion of Rabbi Shimon ben Lakish, who said that a woman can establish a fixed menstrual cycle even during the days that she has zava status, but a woman does not establish a fixed menstrual cycle during the days of her impurity due to menstruation, as any bleeding during these seven days is merely a continuation of her original menstruation. According to this opinion, it is well, and one can understand the mishna. But according to the opinion of Rabbi Yoḥanan, who said that a woman can establish a fixed menstrual cycle during the days of her menstruation, let her examine herself, as perhaps she will establish a fixed menstrual cycle.

The Gemara explains that Rabbi Yoḥanan could say to you: When I say that a woman can establish a fixed menstrual cycle during the days of her menstruation, that applies only in a case where the first two instances of her fixed cycle were established when she first saw blood from a stopped source, i.e., she saw blood on those particulars days at the outset of her period. But when she first saw blood from an open source, i.e., when the first two instances that she experienced bleeding on those particular days was in the middle of her menstrual period, I did not say that she establishes a fixed menstrual cycle, and therefore there is no need for her to examine herself.

§ The mishna teaches: All women must examine themselves each day, except for a menstruating woman, whose impure status is known, and a woman after childbirth who is observing the period of the blood of purity. The Gemara explains: It may enter your mind that when the mishna mentions a woman who is observing the period of the blood of purity, it is referring to one who is finishing the period of impurity following a birth and is anticipating observing the period of the blood of purity. In other words, her days of impurity are ending and she is about to start her days `of purity, and the mishna is stating that there is no need for an examination to conclude her days of impurity before starting her days of purity.

The Gemara analyzes the mishna in accordance with this interpretation. This works out well according to the opinion of Rav, who said that blood after birth and blood of purity both come from one source, and the Torah deemed blood after birth impure, and the Torah deemed blood of purity pure. According to this opinion, it is well, and one can understand the mishna, since even if she emits blood continuously through the end of her days of impurity into her days of purity, the blood during her days of purity is pure.

But according to the opinion of Levi, who said that there are two distinct sources, one for blood after birth and one for blood of purity, she should be required to examine herself at the end of the period following birth, as perhaps that impure source of blood after birth had not yet stopped flowing. The Gemara explains that Levi could say to you: In accordance with whose opinion is this ruling?

Traduction : The William Davidson digital edition of the Koren Noé Talmud, with commentary by Rabbi Adin Even-Israel Steinsaltz.

Nidah 11a explores rabbinic debates on menstrual cycles tied to pregnancy, nursing, and whether repeated jumping establishes a fixed pattern.