Impurity in Life and in Death

  • Rav Yoel Bin-Nun

This shiur is dedicated in memory of
Rabbanit Frieda Heller z"l
whose yahrzeit falls on the third of Iyar,
by her granddaughter, Vivian Singer.


  1. Impurities related to death

The parashot of Tazria and Metzora deal with matters of purity and impurity as part of the broader context of Sefer Vayikra, in which the most significant ramifications of this distinction concern the prohibition on entering the Sanctuary or eating from sacrifices and other sanctified foods while in a state of ritual impurity. Impurity is the opposite of the very essence of the Sanctuary; purity is a precondition for entering.

Ramban hints to the significance of the state of impurity in his commentary at the end of Parashat Metzora (Vayikra 15:11), and he discusses the concept further in his commentary on the unit devoted to impurity through contact with a corpse (Bamidbar 19:2). He explains that the common denominator or theme connecting all the different forms and categories of impurity is some degree of contact with death.

To this we might add that what we know today about the religion of Ancient Egypt is that its main focus was death. Elaborate funerary practices included the handling of the dead, mummification, provisions for the afterlife, and burial sites (pyramids, royal tombs). The exodus from Egypt therefore brought us out of the Egyptian world of death, to a life of purity in accordance with the Torah. The Torah prohibits us, in three place, from returning to Egypt (Yerushalmi Sukka 5:1) and also prohibits communing with the dead (Devarim 18:11).[1]

The impurity related to certain types of animals is also connected to death. The impure animals convey impurity only when they are dead; someone who touches a live pig does not contract impurity. On the other hand, the carcass of a “pure” animal (which died of natural causes or was killed) does convey impurity; the only way in which its flesh retains its pure status is through ritual slaughter (shechita).

Life does not impart impurity; only death conveys impurity.

Following its categorization of the pure and impure animals, the Torah moves on to the impurity of a birthing mother, followed by the unit on tza’arat, and then comes back to the impurity of seminal issue and blood. Here too, the common denominator is some or other level of contact with death.

A man’s sperm produces life. A woman’s menstrual blood is also part of the system that creates life. The fusion between male sperm and female ovule, functioning within this framework, creates life. Impurity appears when these systems die and are flushed from the body. Where there is fertilization and a pregnancy develops, the system that supported the fetus in the womb is discharged following childbirth, and this, too, renders the mother impure.

Tzara’at entails impurity because it is the death of the skin. Aharon pleads on behalf of his sister, Miriam:

“I pray you, let her not be like one who is dead, whose flesh is half consumed when he emerges from his mother’s womb.” (Bamidbar 12:12)

It is remarkable, and strong support for the interpretation offered here, that Aharon invokes the image of a fetus emerging half consumed in the context of tzara’at.

The common denominator linking the various types of impurity is therefore the presence of or contact with different manifestations of death. To express this idea in the language of our time, we might say that death is a warning sign that affirms the sanctity of life. “Life” means not only the full and complete living of human life, but also that which produces, nurtures, and maintains life, including male sperm, the blood lining the uterus in preparation for or during pregnancy, and the skin that protects the human body in life.

Life and death have both physical and spiritual significance, and our parshiot accordingly have both physical and spiritual meaning. We live in a generation in which doctors and scientists study and recognize, in their professional capacity, aspects of both physical and mental/psychic health. The moral, spiritual, religious aspect of this complex fusion, however, is left to religious scholars and experts in ethics.

In the Torah, however, these spheres are interrelated and always appear together. It is easy to understand why religious Jews in our contemporary society usually seek to highlight the spiritual aspect of these parshiot, but there is no avoiding the physical, medical aspect that is so strongly emphasized in the text. The separation of the different realms that is so familiar to us today is entirely foreign to the understanding of Chazal – along with earlier and later commentators, most prominently the Rambam and Ramban, both of whom where physicians themselves. Ramban writes in his commentary that the Holy One, blessed be He, prescribes what the Jewish People must do in order to remain healthy both in body and in psyche. It is therefore not at all surprising that these parshiot address fundamental medical questions, including some concerning a reality not known to us today: the quickly-spreading plague of tzara’at.

Chazal’s teachings show that they studied all that they could from the scholars of their times, from the Greeks and the ancient physicians, and they cite this knowledge with none of the modern squirming and hesitation that afflict us today. The reason for this is that they never saw any contradiction or separation between body and spirit. Both were created by God, Who oversees both realms, guiding us both in life and in Torah.

With this in mind I, too, consulted with doctors who are also Torah scholars before undertaking the interpretation of our parasha.

  1. Impurity of the birthing mother

The parashiot of Tazria and Metzora are bound together in a closed structure. The text first talks about the birthing mother, then the plague of tzara’at, and then the impurity of seminal issue and of menstrual blood, both of which are integrally related to childbirth. In fact, the unit discussing the birthing mother assumes the laws of menstrual impurity as its basis:

And she shall be impure seven days; as in the days of her menstrual sickness shall she be impure. (Vayikra 12:2)

This prompts the question of why the subject of the birthing mother is treated first.

Although the impurities of the birthing mother, seminal issue, and menstrual blood serve to fuse the two parshiot into a single unit, attention should be paid to the fact that some of the laws applying to a birthing mother are unique. As noted, impurity is associated with death, and purity with life. The process of childbirth results (usually) in a live newborn, who neither conveys impurity to the mother nor contracts the impurity of the physical remnants of the pregnancy as they are passed from the body. Hence the special laws applying in this situation. While seminal issue and uterine blood that are expelled always cause impurity, in the case of the birthing mother, there is “impure” blood and “pure” (or “purifying”) blood, a distinction that does not apply to any other category of impurity.

The Torah starts at the point where impurity and purity coexist in the same place. The lining of the uterus, the placenta, the entire system that nurtured the fetus, now concludes its function and dies – but the newborn emerges to life.

And the Lord spoke to Moshe, saying: Speak to Bnei Yisrael, saying: If a woman conceives and bears a male [child], then she shall be impure seven days; as in the days of her menstrual sickness shall she be impure. And on the eighth day the flesh of his foreskin shall be circumcised. And she shall then continue in the blood of her purifying for thirty-three days; she shall touch no sanctified thing, nor come into the Sanctuary, until the days of her purifying are completed. But if she bears a female child, then she shall be impure two weeks as in her menstruation, and she shall continue in the blood of her purifying for sixty-six days. And when the days of her purifying are completed, for a son or for a daughter, she shall bring a lamb of the first year for a burnt offering, and a young pigeon or a turtledove, for a sin offering, to the door of the Tent of Meeting, to the Kohen, who shall offer it before the Lord, and make atonement for her, and she shall be cleansed from the issue of her blood. This is the teaching for her that has born a male or a female. And if she is not able to bring a lamb, then she shall bring two turtledoves, or two young pigeons – the one for the burnt offering and the other for a sin offering, and the Kohen shall make atonement for her and she shall be pure. (Vayikra 12:1-8)

Perhaps the most perplexing question arising from this unit is the disparity between the “days of purifying” for a male child and the count that is twice as long for a female. Early and later commentators alike have struggled with this problem, with most relegating it to the category of laws whose reasons we cannot understand.

An interesting dispute in Massekhet Nidda (35b-36a) between the Amora’im Rav and Levi concerns the question of whether the “pure” blood and “impure” blood share the same source or issue from two separate sources. In other words, is it the same blood, which the Torah simply decrees to be pure in some cases and impure in others, or is there some mechanism whereby the source of “impure” blood closes and the source of “pure” blood opens?

In the gemara, Levi maintains the view that pure blood and impure blood cannot emerge from the same source. There must therefore be two distinct physiological processes occurring during childbirth. One is the expulsion of impure blood from the uterus; the other is the oozing of pure blood, perhaps from cuts that open over the course of the labor and delivery.

Rav disagrees, arguing that there is one source of blood, and it is the Torah that declares it impure in one case and pure in another.

All the doctors I consulted gave the same answer: the blood is the same blood. While there is a fundamental difference between the bleeding at childbirth and menstrual blood, there is no fundamental difference between the bleeding of the first, second, or third week after childbirth. The heaviest flow is usually during the first week after the birth, with up to about forty days of lesser bleeding.

Chazal reach the same conclusion, and are quite unequivocal in their ruling that the halakha follows the opinion of Rav, whether this entails stricter or more lenient practice. Thus, all the poskim agree that the blood is from a single source and lasts forty days (7 + 33), whether the newborn is male or female. The attempt to adopt a stricter view to cover both opinions is explicitly rejected in the gemara. The only opinion that is accepted is that of Rav; there is only one kind of bleeding.

However, both the dispute and its conclusion, as echoed in the information provided by the doctors I spoke with, serve only to intensify the question. If the blood is the same blood, why does the Torah impose a double period of impurity following the birth of a daughter, in comparison to the period following the birth of a son?

Another dispute, this time between Tanna’im, concerns a question tangentially related to the previous one. Does the formation of a male fetus and of a female fetus follow the duration set down in the unit discussing a birthing mother? R. Yishmael maintains that the formation of a male fetus is complete after forty days, while the formation of a female fetus is complete after eighty days. In other words, R. Yishmael maintains that from the time of their very formation, there is a fundamental physiological difference between a male and a female. According to this view, a miscarriage that occurs between the forty-first day and the eightieth day causes the mother the impurity of a male, but not of a female.

However, in Massekhet Nidda (30b), Chazal reject the view of R. Yishmael and conclude that the formation of a fetus – whether male or female – is complete after forty days (six weeks, in modern medical parlance).

The gemara records that the Sages on both sides of the argument invoked the physicians of Cleopatra, Queen of Egypt:

They told R. Yishmael: It is said of Cleopatra, Queen of Alexandria, that her handmaids were sentenced to death by royal decree. Upon examination it was found that both [male and female embryos] were fully formed on the forty-first day.

He replied: I bring you proof from the Torah, while you bring me proof from fools?!

What was his proof from the Torah? Seemingly, the argument that the Torah prescribed impurity and purity with regard to a male, and prescribed impurity and purity with regard to a female [and just as the fashioning of the former corresponds to his impure and pure periods, so the fashioning of the latter corresponds to her impure and pure periods]. But to this the Sages had already replied: The duration of the fashioning period cannot be deduced from the period of impurity…

R. Yishmael then told them: It is said of Cleopatra… that when her handmaids were sentenced to death by royal decree, an examination found that a male embryo was fully formed on the forty-first day, while a female embryo on the eighty-first day.

They said to him: Proof is not brought from fools…

In other words, the findings of autopsies on fetuses in Ancient Egypt were also recorded as two different versions, corresponding to the dispute among the Sages.

It is not clear why proof had to be brought from the rather strange story of Cleopatra’s maidservants to support the two different opinions. After all, miscarriages are, unfortunately, not a rare occurrence, and the stage of development of the fetus after forty days could be established without invoking the specialists in Egypt.

However, the entire dispute turns on the attempt to find some physiological support on which to establish the halakha, in accordance with the Torah’s distinction between male and female with regard to the impurity of the birthing mother.

In other words, in both instances, and in both disputes, the gemara rejects the attempt in principle to establish some difference between the nature of the bleeding following the birth of a male or a female, and the duration of the formation of the fetus in each case.

Thus, we come back again to the same question. If the Creator and the Giver of the Torah created one single source for the bleeding of a birthing mother and established the same duration – 40 days – for the formation of a fetus, be it male or female, then why does the Torah set down two different periods of impurity and purity following the birth of a male or a female?

After contemplating this question for many years, I asked my friend, Prof. Simcha Yagel (a senior gynacologist who is also knowledgeable in Torah), whether eighty days might represent the average period of time that it might take for a new mother to resume menstruation and conceive another pregnancy. His answer was that this was entirely reasonable.

In light of this, we can understand the Torah’s law about the impurity and purity associated with the birth of a daughter. A daughter will, God willing, experience pregnancy and the development of new life within her when the time comes. Thus, the Torah sets down doubled durations for a female birth, reflecting the return of the life-producing system to its regular path and functioning.

  1. What is tzara’at?

Is tzara’at a disease or ritual impurity? Can we identify the tzara’at discussed in the Torah?

Almost all the scholars who have addressed this subject conclude that we are unable to identify tzara’at; the symptoms described in the Torah are not those of the disease known to us as leprosy (which is the way ‘tzara’at’ is usually translated). Leprosy, or Hansen’s Disease (named after the physician who discovered the bacteria that causes it), shows no white hair, because the hair in the lesion is shed. On the other hand, it entails inflammations and swelling of limbs and even loss of extremities, of which no mention is made in Sefer Vayikra.[2]

Moreover, Hansen’s Disease develops very slowly. Shutting a person in quarantine for seven days and then inspecting him to see whether there is any change would be futile.

All of the above has led most scholars to conclude that the ancient tzara’at referred to in Sefer Vayikra no longer exists, or at least is not familiar to us. Although it was known in the time of the Sages – who discuss it in Massekhet Nega’im – it appears to have died out sometime between their period and the present day.

Let us dwell for a moment on the color of tzara’at in the Torah, in contrast to Hansen’s Disease, and propose possible ways of understanding the differences.

Many skin diseases display a red rash. Here, in contrast, we find a white rash – or at least an absence of pigment inside the lesion. The sores characterizing Hansen’s Disease have a raised red outline, while the center lacks pigment.

In contrast, the whiteness described in the Torah is not merely a lack of pigment. Chazal (Nega’im 1:1) teach that the baheret (bright spot) and set (rising) are actually four distinct shades: baheret can be either “white like snow”  or “white as the lime of the Temple,” while set can be “white as wool” on a newborn lamb, or “white as the membrane of the egg” beneath its shell. Thus, there is a significant difference between Hansen’s Disease and the tzara’at described in the Torah.

Two explanations might shed light on this. Ramban writes:

The Torah seeks the purity of Israel and their bodily hygiene, and [therefore] removes this sickness from its start, for these symptoms are not yet full-blown tzara’at, but they may develop into it. The physicians write in their books that bright spots should cause alarm for fear of tzara’at. Therefore the Torah calls them, at their very first appearance, “a lesion of tzara’at” – which is not full-blown tzara’at. If the symptoms of impurity are clearly manifest following the period of quarantine, such that it may be said that “this is tzara’at,” then it may be full-blown tzara’at. Sometimes it is said of the impurity, “then the Kohen shall pronounce him impure; it is tzara’at” (Vayikra 13:8). This means to say that he is impure with it from this point, since it is a lesion that will unquestionably develop into tzara’at, and it is proper that this individual now be separated from the people. Similarly, “then the Kohen shall pronounce him impure; it is tzara’at” (Vayikra 13:22) means that it is a large lesion that will not heal, but will continue to grow and to spread, as it has done. (Ramban, Vayikra 13:3)

In light of Ramban’s explanation, we can understand the reason that while the harsh symptoms of acute swelling and loss of extremities that appear with Hansen’s Disease may be hinted to in Aharon’s plea to Moshe concerning Miriam, they are deliberately not set forth explicitly in the Torah. The Torah establishes an extensive independent system aimed at halting the development of the full-blown, grave condition. For this reason, the Torah speaks about purification from the early symptoms, rather than from the disease itself.

In his usual manner, Ramban offers his medical explanation as part of his commentary because the Torah makes no distinction between bodily health and hygiene and the proper moral guidance and purification of the soul; God created both.

A second explanation, complementing Ramban’s commentary, was offered to me by Dr. Zerem Freier (a pediatrician, researcher, and Torah scholar), who studied the subject in depth. His theory is historical in nature. He argues that the bacteria discovered by the Norwegian physician Hansen is a mutation, a weakened form of the acute virus that existed at the time of the Torah. The Creator gradually eased the terrible threat of tzara’at over the course of generations, through a natural process.

In any event, the main lesson from these parshiot is that we should be cautious and keep away from any disease that can spread, and strict boundaries should be set in place to protect the public – as is the practice of the Ministry of Health in any civilized country. In the same way, the authorities whose concern is morality and Torah, and those in charge of law and order, must likewise set firm and strict boundaries in place – for instance, concerning alcohol and drugs (which, as we know, can lead to tragedy, especially among youth, on the roads, etc.).

  1. Running seminal issue (zav)

In the unit devoted to the zav, Ramban writes:

The reason for the impurity of a running issue is because it is a serious disease, among the contagious sicknesses, and it requires a sacrifice to give thanks to God for having healed him and purified him, as well as a sin offering, to make atonement for his sin, so that he will not suffer further disease. (Ramban, Vayikra 15:11)

Once again, Ramban highlights both the medical and the religious aspect of a man’s “running issue” of semen.

Chazal exert tremendous efforts to limit the phenomenon of the zav. In the mishna we find:

There are seven lines of questioning for the zav... (Zavim 2:2)

In other words, wherever there is any possibility of attributing the issue to some other cause – be it something “that he ate, or drank, or carried, or if he had jumped, or had been ill, or had seem something [arousing], or had entertained [inappropriate] thoughts” – then it is attributed to that cause, and his impurity falls not under the category of zav, but rather the lesser impurity of “seminal emission” (keri), which renders the man impure until evening and requires only regular immersion.

In establishing these standards, the Sages ensured that the stringent rules pertaining to the zav would apply only in the case of a running issue that was truly the result of disease.

R. Akiva was even more lenient, ruling that if the subject had consumed any food or any drink, whether detrimental or healthy, he could not be pronounced a zav, and should be treated as impure only under the category of keri.

The Sages, appreciating the far-reaching implications of this blanket ruling, objected: “But henceforth no-one will ever be considered a zav!” To which R. Akiva replied, “You are not responsible for zavim.” Meaning, it is not your job to ensure that there are people amongst Am Yisrael who are defined as zavim.

With regard to the examination of the zav, Ramban does not adopt R. Akiva’s view, but the tendency among both R. Akiva and the rest of the Sages was clearly to limit the incidence of zav to a minimum.[3]

  1. Nidda and zava

When it comes to the issue of a woman’s blood, there is likewise a normal, healthy situation and a situation that is not healthy. The normal, healthy situation is menstrual blood:

She shall be seven days in her menstrual separation. (Vayikra 15:19)

While in this state, a woman conveys ritual impurity to whatever she touches, but she requires no sacrifice nor (according to the Written Law) a count of seven clean days prior to immersion. The counting of seven days is required only for a zava, whose bleeding has an unhealthy aspect to it, requiring recovery, atonement, and the bringing of a sacrifice.

According to the Written Law, menstrual blood renders a woman ritually impure whether she bled for just one day or for several days. She examines herself to ensure that the bleeding has stopped, immerses herself, and is thereby rendered ritually pure. It is only when the bleeding continues, manifesting disease, that she must count seven days and only then immerse.

How, then, did we arrive at the universal practice whereby Jewish women count seven clean days after every regular menstrual period (and every occurrence of uterine bleeding)? According to the gemara (Nidda 66a), “The daughters of Israel accepted the stringency upon themselves.” Following the destruction of the Temple, there was no longer any critical need to draw a distinction between a regular nidda (i.e., healthy menstrual blood), a zava ketana (continued bleeding for one or two days), and a zava gedola (continued bleeding beyond that), who would have been obligated, in Temple times, to bring a sacrifice. The detailed distinctions and definitions concerning how many times spotting was observed on how many days after the end of the menstrual period had lost their practical relevance in terms of the permissibility of approaching the Sanctuary. From that point, Jewish women adopted the general rule seven clean days are observed following any situation of uterine bleeding, whatever its duration.[4]

In any event, a rather strange situation is created whereby Chazal exert themselves to limit situations to which the definition of zav would apply, requiring seven different lines of questioning with a view to discounting it, while any instance of uterine bleeding causes a woman to count seven clean days, a procedure stipulated in the Torah only for the case of a zava gedola.

I heard an interesting explanation for this disparity from respected women who suggested that the women sought some control over their fertility, and the stringency of counting seven clean days after any instance of bleeding would often result in the date for immersion falling after their ovulation. This served to prevent pregnancies from following too closely after one another, without entailing any measures that would present halakhic problems.

The painful price of this approach is borne by religiously-observant couples when the wife has a short ovulation cycle. In these instances, the observation of the seven clean days sometimes prevents them from achieving a pregnancy (a phenomenon referred to today as “halakhic infertility”). One of the very difficult questions that these couples ask is whether they might be permitted to revert to the original Torah law until such time as they have achieved pregnancies and borne children.

It is interesting to note that poskim throughout the generations continue to cite the original Torah law, even though it is not normative practice. I once asked a prominent halakhic authority in this sphere what he thinks will happen when the Temple is rebuilt. Will women still count seven clean days for every issue of blood, or will we go back to the original law? And if we do not go back to the original law, with its distinctions among different durations of bleeding, how will we know who is obligated to bring a sacrifice and who is not?

After thinking about this for a few moments, the posek cited Ramban’s teaching (on Massekhet Nidda) that two counts cannot be maintained at the same time. Therefore, when the Temple is rebuilt, we will have to revert to the original Torah law. It is perhaps for this reason that poskim still cite the Torah law in their rulings in this realm.

  1. Immersion of the nidda

In conclusion, I wish to add a few words about what Chazal refer to as tevila (immersion). The Torah always mentions “bathing (rechitza) in water.” The word tevila is not used. This causes some people to question the halakha, claiming that “nowhere does the Torah prescribe immersion.”

R. Eliashiv Knohl from Kfar Etzion explains simply and clearly the very different meaning of the term tevila as used in the Torah:

 [It refers to] light contact with fluid, blood, or oil, as in, “He shall dip (ve-taval) them and the living bird in the blood of the bird that was killed” (Vayikra 14:6), or the dipping of a finger – “And the Kohen shall dip (ve-taval) his right finger in the oil that is in his left hand, and shall sprinkle of the oil with his finger seven times before the Lord” (Vayikra 14:16). The Torah never mentions the concept of “dipping” (tevila) in relation to the entire body; the term is used only to describe light contact. The term “tevila” (immersion), as used by Chazal, means exactly the same as the term “rechitza” (bathing) used in the Torah. The Torah speaks of “bathing in water,” and Chazal (in the later period) call this bathing “immersion.”

May it be God’s will that we merit His purifying waters.

Translated by Kaeren Fish


[1]  Including at Meron! R. Shimon bar Yochai would send away those who visited there because of the impurity of the graves.

[2] These symptoms might be hinted to in the context of Miriam’s tzara’at: “I pray you, let her not be like one who is dead, whose flesh is half consumed when he emerges from his mother’s womb” (Bamidbar 12:12). However, the discussion of tzara’at in Sefer Vayikra makes no mention of swelling or loss of limbs.

[3] It is quite surprising to discover that witnesses in a criminal case are also subjected to seven questionings (Sanhedrin 85a), and R. Akiva (along with R. Tarfon) declares that he, sitting on a Sanhedrin, would never sentence someone to death (Makkot 7a), but rather would question and interrogate the witnesses with a view to rendering them invalid, and thereby avoid the death sentence. We might then ask why the Torah stipulates in so many instances, “he shall surely be put to death.” The answer is that it comes to teach us how serious these transgressions are in God’s eyes.

[4] There are women today who claim that this was a stringency imposed by men, who chose to present their own stringent view as one voluntarily taken on by the women. However, from experience, the possibility of Jewish women adopting a stringent but simple and straightforward general rule is at least as reasonable as the possibility of men doing so. Cleaning for Pesach offers just one comparative situation.