A New Look at the Laws of Niddah

Women Waiting to Start Shiv’a N’kiyim, Halachic Infertility, and the Hetter of the Rambam

February 20, 2014

Yoreh De’ah, 196:11:

A woman who emits seed during her days of counting (the “shiv’a nekiyim“): If it is within six ‘onoth (time periods defined as either from sunrise to sunset or sunset to sunrise, in essence three full days) of when she engaged in intercourse, it invalidates that day (of the emission). Therefore, one who engages in intercourse, sees blood (unrelated to the prior relations) and then performs hefseq tohara, may not begin to count her shiv’a nekiyim until six full ‘onoth [pass from the time she had intercourse] lest she emit seed [therefrom]. Therefore, she does not start counting until the fifth day from when she engaged in intercourse. For example, if she engaged in intercourse Saturday night, she would not begin her count until Thursday, as we hold that seed does not spoil until six ‘onoth have passed, i.e. a full 72 hours. 

The Rema brings even stricter opinions. This halacha is considered a staple of modern day nidda observance; this website is an example of the mainstream rabbinic approach to the concept. Note the over riding assumption that a woman must wait a certain amount of time before she can start her nekiyim.

The question I always had with this halacha was,  “Why not let her take that chance? Either she’ll start nekiyim ASAP, and she will not emit seed, or if she starts early and does emit, then let her ruin that first day of the count. Why should we assume the worst and make her delay the start of nekiyim?”

Some years ago, R’ Schachter came to speak at Lander College. The first time was to sit on a panel with Rabbi Lau, Rabbi Shear Yashuv Cohen, and Rabbi Tendler, and discuss Religious Zionism in the post-Zionist era, and the other time was with Rabbi Belsky, Rabbi Genack, and Rabbi Slifkin to discuss the kashrus of exotic species. I do  not specifically recall which event it was, because the personal discussion we had was after the event and downstairs in the main beis medrash. There, Rabbi Daniel Freund and I spoke to him about the presentation we had recently attended on the topic of helping halachically infertile couples. We suggested that the “Humra D’ Rabbi Zera” could be avoided. Here is Maimonides’s explanation of the rule (Issurei Bi’a 11:4, Touger edition):

In addition, Jewish women accepted a further stringency upon themselves. They accepted the custom that wherever Jews live, whenever a Jewish woman discovers [uterine] bleeding, even if she does not discover more than a drop the size of a mustard seed and the bleeding ceases immediately, she must count seven “spotless” days. [This stringency applies] even if she discovered the bleeding during her “days of niddah.”

Whether the bleeding continued for one day, two days, an entire seven days, or longer, when the bleeding ceases, she counts seven “spotless” days as is required of a major zavah and immerses on the night of the eighth day despite the fact that there is a doubt whether she is a zavah. Or she may immerse during the day on the eighth day in a pressing situation, as explained. Afterwards, she is permitted to her husband.

We argued that because keeping this stringency causes many women to avoid intimacy while they are ovulating, every husband should nullify his wife’s assumed vow to keep this rule the day they marry. (See Hilchoth Nedarim, 11-13) After all, if he knew at the time of his marriage that her observance of this stricture would make them childless, he would certainly want her not to keep it.

Rabbi Schachter answered that Rabbi Zera’s rule has more force than a private vow, and such is the answer every other rabbi has given me. He claimed it would take a bona fide Sanhedrin to undo such a law. I still maintain that it should not, as no where does it say that Rabbi Zera’s stringency was an enactment of the Sanhedrin. It is as the Gemara has it: “the daughters of Israel dealt strictly with themselves.”

Rabbi Schachter then offered that there is a further issue with regard to halachic infertility. He claimed that doctors had told him that it was a matter of solid fact that women did not emit seed from their wombs after intercourse, although seed that does not get beyond the cervix routinely exits the birth canal. Thus, the basis of the above law from Yoreh Deah is removed.

The problem though, was that that law had a solid basis in the following Mishna, which itself was based on a clear understanding of a verse from the Torah (Shabbath 9:3):

Whence is it [to be inferred] that a woman who emits semen on the third day [after coitius] is unclean? From the text, “And be ready against the third day.” (Exodus 19:11)

When Moses transmitted this command to the people (Exodus 19:15) he added the caveat, “do not approach a woman.” This shows that Moses himself established a three day quarantine for the people in preparation for the Revelation at Sinai, presumably because the women needed three days to make sure that they would be free of any remaining seed from prior relations. As Rashi says on that verse,

Do not go near a woman: [to have intimacy with her] for all these three days [of preparation], in order that the women may immerse themselves on the third day and be pure to receive the Torah. If they have intercourse within the three days, the woman could [involuntarily] emit semen after her immersion and become unclean again. After three days have elapsed [since intercourse], however, the semen has already become putrid and is no longer capable of fertilization, so it is pure from contaminating the [woman] who emits it. — [from Shab. 86a]

It should be noted that the standard of purity for receiving the Torah was different from the one discussed in Yoreh De’ah, but the point remains the same. Seed might come back some days later, and there are apparently halachic consequences.

Or so it seems.

Recently Rabbi Bar Hayim wrote the following. Note points 5 and 6, and then 7, where he brings Maimonides’s ruling in straight contradiction to the rule of the Shulhan Aruch, above.

Hilkhoth Nida – Basic Concepts and Requirements in Brief

 Yom 5, 21-10-65 — 21 Teveth 5773 — 03-01-2013


  1. This is a very frustrating mitzvah for me!  Although we do keep it fully.  I’m so confused about many things regarding Taharat Mishpacha.  Isn’t it true that when a woman is Niddah (or a Zava?), the first seven days are d’oreita, and the seven clean days are actually a machloket?  Why is it that women can forgo the first seven days but never the second?  The seven clean days seems so excessive to me!
  2. In your view, must a woman wait 4 or 5 days before doing a hefsek tahara?
  3. Is a moch dachuk necessary?  I learned that it was a chumrah and never did them, personally.
  4. I realize some of these things are “Sephardi v. Ashkenazi” and I’d like to know where you stand.
  5. I also tend to have issues with staining and have trouble getting clean bedikot the first few days of the seven, so I’m always seeking out ‘leniencies.’



  1. Very good news…
  2. Regarding your other questions: Min HaTora, a menstruating woman (i.e. at the usual time for her menstrual cycle) is ttame for 7 days, whether she saw blood for 1 day or up to and including 7 days. She must then peform a b’dhiqa, and at night, i.e. the beginning of the 8th day, she goes to the miqwe. Those 7 days are known as Y’me Nida. Where the bleeding continued beyond the initial 7 days, see below no.3.
  3. If, however, blood is seen during the 11 days following those first 7 days (which occurred at the time of her usual menstrual cycle), it becomes more complicated. If she saw blood for 1 or 2 days, she must wait one clean day for every day of bleeding, and then go to the miqwe after performing a b’dhiqa. If she saw blood for 3 consecutive days, she must wait for the bleeding to cease, perform a b’dhiqa, and count 7 Clean Days before going to the miqwe on the night of the 8th day. Min HaTora, it is only in this case that a woman must count 7 Clean Days. These 11 days are known as Y’me Ziva, because only during these days can a woman become a Zava. After those 11 Y’me Ziva, i.e. after 18 days from the beginning of the usual menstrual cycle, any bleeding is considered Nida and not Ziva. (This is the view of all Rishonim. The view often attributed to Rambam is based on a corrupt text (as found, for example, in the very inaccurate Vilna edition) and is quite impossible. For the correct text, see MT Hilkhoth Isure Biya 6:5).
  4. All of the above is min HaTora. Due to the possibility of confusion, the Hakhamim decreed that all bleeding be considered to have occurred during the 11 Y’me Ziva, which means that normal, menstrual bleeding that lasts 3 or more days must be followed by 7 clean days.
  5. In addition, the Talmud informs us that Jewish women took upon themselves the added stringency of always counting 7 Clean Days after seeing even a drop of blood and no matter for how long the bleeding lasted (TB B’rakhoth 31aM’ghila 28b and Nida 66a). See Rambam’s MT Hilkhoth Isure Biya 11:4,
  6. These humroth (strictures) are understood by many today to be problematic. The humroth mentioned above can frequently result in ‘Halakhic infertility’, i.e. the woman missing her window of opportunity for conception due to ovulation occuring during the Seven Clean Days. This is a very serious issue on a number of levels, not the least of which is the demographic future of the Jewish people. On a different note, I have heard serious, God-fearing Jews state that the lengthy abstinence (usually 12 days or more) from marital relations can have a negative impact on the marriage. These issues cannot be swept under the carpet. I assume that when a critical mass within ‘Am Yisrael wake up and establish a Beth Din Gadhol, as is our duty according to the Tora (see Rambam’s MT Hilkhoth Sanhedrin 1:4), these issues will feature prominently on the agenda.
  7. It is not necessary to wait 4 or 5 days before performing an Hephseq Tahara and starting to count the 7 Clean Days. If the menstrual bleeding lasted only 1-3 days and a b’diqa is performed and found to be clean, one may begin counting the 7 Clean Days immediately. See Rambam’s MT Isure Biya 11:13 and Hilkhoth Nida of Ra’ah 1:2.   
  8. A Mokh Dahuq (see Shulhan ‘Arukh YD 196:1) – a humra based on the recommendation of the Rashba (but not a requirement) and not mentioned by Hazal or other Rishonim – is unnecessary. (This is one more example of R. Yoseph Karo z’l not following the rules that he himself laid down in the introduction to his Beth Yoseph commentary on the Tur, in which he states that he will follow the unanimous or majority opinion of three Rishonim: Riph, Rambam and Rosh. None of these Rishonim require a Mokh Dahuq.)

 May HASHEM bless you in all things

Rabbi Bar Hayim is not the first Rabbi who has ruled that mokh dahuq is unnecessary. Rabbi Elazar Raz told me that because it causes undue irritation for many women, it should not be done at all. Other observant OB/Gyn’s have concurred.

Now, the question can be asked against Maimonides: does he not hold of the Mishna’s understanding of the verse concerning Moses’s three day quarantine? The answer is NO. He does not exactly understand the verse as Rashi or the Babylonian sages understood it, and therefore does not hold of the Shulhan Aruch’s rule. How do I know? Because of what he wrote concerning Moses’s decision in the Guide to the  Perplexed (3:33, Freidlander translation):

The Law is also intended to give its followers purity and holiness; by teaching them to suppress sensuality, to guard against it and to reduce it to a minimum, as will be explained by us. For when God commanded [Moses] to sanctify the people for the receiving of the Law, and said, “Sanctify them today and tomorrow” (Exod. xix. 10), Moses [in obedience to this command] said to the people, “Come not at your wives” (ibid. ver. 15).Here it is clearly stated that sanctification consists in absence of sensuality.

That is, the quarantine was for the sake of spiritual preparation in anticipation of the Revelation, not because of some technical rule.

I will now anticipate a problem. Doesn’t Maimonides himself write in his commentary to that Mishna along the same lines as the Gemara cited by Rashi? The answer is yes, but with an important additional detail. “We shall explain this further in the eighth chapter of Miqwa’oth.” The reference is to Miqwa’oth 8:3-4 (Blackman edition):

If one discharges thick drops from the membrum virile, he is unclean, according to the view of R. Eliezer Chisma. If one experienced impure thoughts in the night [during sleep], and on rising found his body heated, he is unclean.~If [a woman] emitted seed on the third day [after copulation], she is clean according to the opinion of R. Eliezer ben Azariah. R. Ishmael says, Sometimes there are [in those two days] four ‘onoth, sometimes five, at other times six [‘onoth]. R. Akiba says, [They are] always five [periods]

Thus, it seems that the Mishnayoth in both Shabbath and Miqwa’oth are not discussing the ramifications of a uterine seminal discharge. Recall that with regards to hilchoth nidda, the concern is with uterine discharges of blood. Urethral or vaginal discharges are by definition not inducing of tum’ath nidda, and in the halacha from Yoreh De’ah above, the concern is with semen that exits the uterus, which would be similar to uterine blood (but not entirely), whereas these mishnayoth are discussingtuma’th qeri, the contamination induced by contacting normal semen, which can be eliminated by washing and subsequent immersion in the ritual bath. Semen within the uterus can not, by definition, be washed out.

Thus, even if Moses was concerned about quarantining the people for three days prior to the revelation, it was not because the women needed time to let whatever seed they had within their wombs to spoil. Rather, he wanted to make sure that no matter who had a chance or not to bathe prior to the revelation, no woman would have any traces of semen left on her anywhere not within her womb.

(This is a good opportunity to recall that although the Midrash claims that the Israelites had a constant and bountiful water source wherever they travelled in the wilderness, the simple meaning of numerous verses in scripture is that they did not. Rather, they had to always make sure to camp near some source of water, and also to take enough with them when they were on the move. Thus, it is likely that not all of the millions of Israelites would have had an opportunity to immerse or bathe within a day of the Revelation. Think about everyone in the family having to shower Friday afternoon. It has to be coordinated. How much more so for an entire nation in the desert.)

In conclusion: The Talmud does not necessarily assume that women could potentially emit seed from their wombs within three days of intercourse, R’ Schachter’s doctors are on to something, and Maimonides had good reason to not hold of the Shulhan Aruch’s halacha, above, because even according to the Shulhan Aruch it is possible for a woman to start her seven clean days ASAP as  long as she both finishes menstruating and thoroughly cleans her cleans her genitals before trying to obtain a clean check.

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