– Author: Rav Sam Millunchik

The brit mila ceremony performed on every Jewish male includes a practice called metzitza, drawing the blood out from the location of the mila. This practice is ancient, with roots in our earliest sources. In the last two to three hundred years, there have been those who wish to alter the practice of metzitza, or even eradicate it completely.

Where Does Metzitza Come From?

The origin of the practice of metzitza can be found in our most authoritative halachic source – the Talmud. The Gemara states[1] that a mohel who does not perform metzitza is no longer allowed to perform britot. This is because, the Gemara states, it is dangerous not to perform metzitza, a practice that Chazal evidently thought had medical benefit. The Rambam[2] explains that the purpose of metzitza is to draw the blood from the “distant places,” presumably to assist in the healing process. Indeed, this is considered to be so critical that the Gemara rules that even though there is chillul Shabbat when sucking the blood on Shabbat, it is nevertheless required. This halacha is brought by the major poskim[3] and has become a normative part of the brit mila ceremony.

 Is Metzitza M’akev the Mila?

Concerning any mitzvah, if something integral is missing in the performance of that mitzvah, the mitzvah is not considered to have been performed. In halachic parlance, this is called m’akev, where the action that wasn’t performed, or was performed incorrectly, is “holding back” the proper performance of the mitzvah. In the case of brit mila, there are three major steps: Cutting of the outer foreskin (mila), tearing and pealing back of the inner foreskin (peria), and sucking of the blood (metzitza). The first two steps are universally accepted to be m’akev – there is no mila without cutting of the foreskin itself, and the Mishna[4] writes that “if one circumcised without performing peria, it’s as if he didn’t perform the circumcision at all.” There are no explicit sources on the issue of metzitza’s place in the ceremony of brit mila other than the Gemara quoted above, and as a result, there has been some discussion as to whether or not the performance of metzitza is m’akev. The Ran[5] in his discussion of when the mila process is considered completed as regards the ability to make corrections to the foreskin on Shabbat, writes:

ומסתברא דכל זמן שהוא מתעסק בצרכי מילה כגון חתיכתה ופריעתה ומציצתה לא מקרי פירש דכולהו צורך מילה נינהו אבל אם סילק ידיו אחר מיכן היינו פירש אף על פי שעדיין יש לו ליתן אספלנית וכמון וחלוק דהני צרכי רפואה נינהו. ואפי’ במציצה עצמה יש לעיין דכל שפרע הרי סיים צרכי מילה ודילמא המציצה מיקריא רפואה ולא צורך מילה היא וצ“ע.

It is logical that the entire time that one is involved in the performance of the mitzvah of mila, e.g. cutting the foreskin, peria, and metzitza, one is not considered to have finished the mitzvah, for all these steps are part of the mitzvah. However, if he has already completed those steps, it’s considered as if he’s finished the process, even though he still has to put on a bandage, for this is part of the medical portion of the mila [and not the mitzvah]. And even by metzitza itself it’s unclear [if it’s part of the mitzvah] for as long as one performed the peria, it’s considered that he finished the mitzvah, and maybe one could argue that metzitza is considered part of the medical part of the mila and not part of the mitzvah. This requires further thought.

The Ran is unsure of how to categorize metzitza – is it part of the mitzvah of mila and therefore m’akev, or is it part of the medical part of mila and therefore not m’akev? The Sdei Chemed[6] comments on the Rambam[7] that because of the way that the Rambam structured the halachic citation of this issue, it is clear that he considers metzitza as being m’akev and part of the mitzvah itself. The Ohr HaChaim[8] argues that it is part of the mitzvah of mila itself and brings a pseudo-medical proof. He says that the outer and inner foreskin have corresponding blood within the genital organ, and until this blood is extracted through the process of metzitza, one is not considered to have finished the mitzvah. Additionally, in the traditional piyut (liturgical poem) which Ashkenazi Jews recite during benching at the brit, the following stanza is recited: “May the Merciful One bless the one who circumcises the flesh of the foreskin/and peeled back the inner foreskin and sucked the blood of the wound/the service of the faint-hearted would not be acceptable/if he failed to perform these three actions.” From here it is clear that the author of this piyut considered metzitza to be an integral part of the mila process. However, the Chatam Sofer, in a letter to his student,[9] writes: “And further I say that even if it was explicit in the Gemara that he should perform the metzitza with his mouth, nevertheless since this isn’t part of the intrinsic mitzvah, but rather was instituted to avoid unnecessary danger to the baby, one who performed the mila and peria but not the metzitza has already finished the mitzvah, and the baby is already permitted to eat teruma [only those who are circumcised are allowed to benefit from teruma] and the pascal lamb.”

We can ask the question – if the metzitza isn’t an intrinsic part of the mitzvah, but rather is there only to prevent danger to the baby – if modern science were to tell us that this wasn’t effective, or was even dangerous to the baby, what would be the halacha? Is there room in Jewish law to change a law when the understanding of the reason for it doesn’t apply anymore?

Shinui Tevaim

One of the major mechanisms that the poskim use to deal with changing circumstances and the implications for Jewish law is the concept of nishtanu hatevaim, the idea that the natural circumstances of the world have changed. Once one posits that the reality today is different from the reality at the inception of the law, it becomes acceptable to change the law to accommodate the contemporary context without tarnishing the sanctity of the original law or those who made the law. This is an important theological concept as well, for those who employ it are generally convinced of the infallibility of Chazal in all matters, including scientific and medical, and thus are met with a contradiction – how could it be that Chazal don’t make mistakes, and yet we clearly see that the world doesn’t operate the way that they thought it did? Shinui tevaim is part of the answer to this problem. Another answer, is that although Chazal were spiritual giants, they were not experts in every scientific field, nor were they infallible, and therefore if there is a mismatch between their scientific statements and our empirical observations, we can simply say that they made a mistake; however, as we mentioned, this approach is objectionable to many.

Discussing mila specifically, the Tiferet Yisrael[10] accepts the basic claim that nature today works differently than in the past, and therefore there is no theological problem with the fact that the Gemara seems to contradict reality. However, he insists on relying on the pesak of Chazal in this instance because he thinks that the current medical information is incomplete, and that the medical literature hasn’t explored in sufficient depth the danger of not doing metzitza.[11] Additionally, he claims that in his time the doctors were ambivalent about metzitza and therefore it makes no sense to stop doing something which is an accepted tradition from our forefathers because of a doubt. He does write, nevertheless, that on Shabbat (where there is an issur d’oraita) one shouldn’t do a powerful metzitza, only a light one.

Rav Dessler[12] takes an opposite and extreme stance. He writes that there is no relevance to what we witness in nature, for “it is not the explanation which forces us to mold the halacha around it, but rather the halacha which forces us to come up with explanations.” For Rav Dessler, it doesn’t make any difference what particular reasons were given for the halacha, only that this is the halacha. He writes that Chazal received the halacha as part of the tradition from earlier generations, and therefore if the reasons don’t fit or seem to contradict nature, it is the reasoning which must be adapted, not the halacha. There are obvious problems with such an extreme approach, not the least of which is the immediate ossification of the halacha. One wonders how Rav Dessler sees any halachic modification or development as legitimate, as he seems to view the halacha as immovable. A potential rebuttal of this challenge to Rav Dessler’s opinion appears in the Rambam, who seems to take a position similar to that of Rav Dessler in certain instances.

The Rambam[13] writes that there is no need for the words of Chazal regarding scientific matters to match reality, for they were not received from prophecy, but rather stem from their personal expertise in a particular field or from their consultations with experts. Therefore, if the prevalent understanding at the time that they made their statements was mistaken, there is no reason to think that the words of Chazal carry any more weight than those of anyone else who might be mistaken. The Rambam is careful to point out that this does not affect our appreciation for their words, nor does it mean that they were wrong often, only that when they were demonstrably wrong, there’s no reason to continue to believe in what they say.

This opinion of the Rambam is true as far as the words of Chazal are concerned. However, when it comes to halacha l’Moshe m’sinai, received tradition, the halacha is unwavering, and thus we can understand the opinion of Rav Dessler which we quoted above. The Rambam writes regarding terefot[14] that even were it to be proven that a particular blemish that’s an accepted sign of a terefa isn’t in fact lethal, we wouldn’t change the halacha. Similarly, if one were to find a new sign of a terefa, the laws of shechita would remain unaffected. In this point, it seems that the Rambam and Rav Dessler overlap – where something is demonstrably halacha l’Moshe m’Sinai, there would be no way to accommodate a change to the halacha, even if the nature could be demonstrated to have changed. (we will see a more in-depth defence of this position later in the essay).

This concept of nishtanu hatevaim appears in many different halachic contexts, including in another halacha regarding brit mila. Originally, the halacha was that one would heat up water on Shabbat for a baby who was on the third day after his brit because it was thought to be dangerous if he didn’t wash with hot water. However, the Beit Yosef[15] writes that “this was only for them. For us, however, it’s known that this is not dangerous anymore, and therefore the law s like that of washing anyone else.” The Mishna Berura[16] explains that this is because “nishtanu hatevaim.”

We can now delineate the basic positions towards the use and necessity of the concept of “hishtanut hatevaim.” Rav Dessler puts forward the position that the halacha is an independent entity and does not, in any way, need to match the reality of a given scientific reality. Indeed, Rav Dessler writes that if we find that a halacha seems to contradict reality, it is our understanding that must necessarily change, rather than the halacha. The Rambam takes a middle position, which could potentially fit in with Rav Dessler’s position as well, namely that if something is halacha l’Moshe m’Sinai then it is firmly immovable, whereas a halacha that was espoused solely by Chazal based on mistaken scientific understandings could potentially be altered. A third position is adopted by the Tiferet Yisrael and is brought l’halacha by the Beit Yosef and the Mishna Berura, specifically that nature today works differently than it did in the past, and therefore the halacha changes, whether l’kula or l’chumra. 

Metzitza Today

After our excursion into the concept of shinui tevaim, we can now approach the contemporary issue of metzitza. Already in the early 19th century, there were those who would have liked to abolish the practice, and they applied a tremendous amount of pressure on the Chatam Sofer and other contemporaries of his. In the teshuva of the Chatam Sofer quoted above, he writes in the continuation that he is willing to compromise and allow metzitza through a glass tube. However, he didn’t allow the abolition of the practice altogether, and his student the Maharam Schick[17] took a much harder line. He received a question from a mohel asking how he should behave in a community where they banned metzitza – should he perform the brit anyway, or leave the child uncircumcised? The Maharam Schick writes a fiery response, saying among other things, “this is nothing other than a distortion and abolition, a destruction of boundaries.” He then proceeds to make a number of substantive claims about why we must still perform metzitza. His first claim is that when science makes claims, they make claims based on probability, and we have a rule in halacha that if there is even a small chance that something will be life threatening, we must act to avoid that danger. So too, in this case, he feels that those who want to cancel metzitza are not giving enough weight to the potential benefits of metzitza. It’s important to point out here that this argument could be used in exactly the opposite way – if one could show that the performance of metzitza would pose a danger, it would be incumbent upon us to cease the practice, or modify it in such a way that it would no longer pose a threat. Incidentally, this is exactly what the Chatam Sofer advocated.

The Maharam Shick makes a further claim, one that echoes both Rav Dessler and the Rambam. He writes that much of what Chazal say is based on a received tradition and has the status of halacha l’Moshe m’Sinai, and it is likely that this is one such example. Later, he rejects the possibility that it is possible to apply the principle of “shinui tevaim” in this case for two reasons. First, we do not apply this principle to matters that are  halacha l’Moshe m’Sinai. Secondly, the laws of the Torah are based on the majority of cases and on the idea that a given situation will continue unless otherwise contradicted (rov and chazaka). Based on this, the Maharam Schick writes that since we know that at the time when we were given this detail of metzitza the reality was that it was useful, and because it is potentially a halachah l’Moshe m’Sinai, we cannot change it now in the absence of a clear proof. Therefore, the Maharam Schick writes that if one is unable to perform metzitza, it is better that he not perform the brit at all.

In his volume of responsa Yehuda Ya’aleh,[18] Rav Yehuda Assad writes in a similar vein that it is an integral part of the mitzvah, as evidenced by the fact that it is performed on Shabbat. Additionally, it is a halacha l’Moshe m’Sinai, and therefore must be performed. It is possible to refute his proof from Shabbat, for we know that all things that are life-endangering override Shabbat, and if the Gemara felt that this was something that was required medically, it makes sense that Chazal ruled that it pushes off Shabbat even though it’s not an integral part of the mitzvah. Rav Kook writes[19] that one must listen to doctors where there is a positive action that arises from their claims, such as taking a particular drug which has been proven through experiments to be effective. However, when it comes to refraining from doing particular things, he is more skeptical. He writes that the doctors have opined that it isn’t dangerous to stop metzitza, and this isn’t enough for him to cease the practice. However, what does seem clear is the fact that if it were to be shown to be dangerous, Rav Kook wouldn’t have an issue stopping the practice.

Rav Hershel Schachter[20] writes that Rav Soloveitchik (the “Rav”) was against metzitza in any form, and even asked a mohel to refrain from performing it in his presence. When the mohel insisted, he acquiesced, though he stated that were his father (Rav Moshe Soloveitchik) present, he would never have allowed it. Rav Dr. Moshe Tendler, Rav Moshe Feinstein’s son-in-law, is another vocal and active campaigner against metzitza b’peh.[21]


Whilst a disagreement exists among the authorities as to its exact level of importance in the mila process, metzitzah has been part of the Jewish practice of mila since Talmudic times at least and perhaps beforehand. In the last two hundred years, there has been a movement to abolish or modify the practice. The halachic answer to that question will depend on how strong of a position is taken by the scientific establishment – as we have seen, were metzitza to be shown to pose a danger, one would have to cease or alter the practice immediately, as nearly all mitzvot are abrogated in the face of something which is life-threatening. However, were the practice to be shown to merely be ineffective, or able to be effected in a different manner, it would seem that one would have no legitimate reason to contradict such an entrenched and even venerated custom.

That being said, some serious halachic questions remain – if, indeed the practice is ineffective, why should we allow its practice on Shabbat when drawing blood is an issur d’oraita? We have seen that the nearly unanimous answer to this question is the scientific inability to prove that it doesn’t have medical benefit. Since it could have a benefit, and it’s difficult to prove that it doesn’t, one would have to continue the practice even on Shabbat, unless one could prove that it was actively dangerous. There are those who take such a view, among them Rav Tendler, and there are cases in the news from time to time that relate the death of a baby to a mohel who transferred a disease to the child.

The question remains – is this a proven connection, and further, if this is an extremely rare occurrence and poses a small statistical danger, is that enough certitude to discontinue a major custom? As we wrote above, it is difficult to prove that it has no medical benefit, and indeed one could imagine an argument where the very low probability of becoming infected is compared to the possibility that it is medically effective, and one chooses to continue performing metzitza. Ultimately, each human is responsible for his choices, both in this life and the next, and will have to stand before the Creator in judgement of his actions – there is no clear path here, and it seems that one should do what he thinks is best after careful consultation with one’s rabbi and doctor. One might also consider that there are many poskim who approve metzitza with a glass tube, which may alleviate some of the more pressing concerns. May Hashem guide our actions for the sake of Heaven.

[1] Shabbat 133b: האי אומנא דלא מייץ – סכנה הוא ועברינן ליה

[2] Hilchot Milah 2:2

[3] Rif, Shabbat 53a (his pagination); Ran (ibid.); Rosh (19:2),

[4] Shabbat 19:6: מל ולא פרע את המילה, כאילו לא מל

[5] Chiddushei HaRan (Hameyuchas lo), Shabbat 133b

[6] Kuntres Metzitza

[7] Hilchot Mila 2

[8] Vayikra 12:3

[9] R. Horowitz, brought in Sefer HaBrit, p.215

[10] Boaz, Shabbat 19:1

[11] It is important to point out that this is a logically dubious claim, for all it takes is one positive example to prove the positive, but a lack of evidence (which is the basic claim of the Tiferet Yisrael) does not prove the negative.

[12] Michtav Me’Eliyahu 709, Footnote 4

[13] Moreh Nevuchim 3:14

[14] Hilchot Shehita 1:12-13

[15] O.C. 331

[16] O.C. 331:31

[17] Responsa Maharam Schick, Y.D. 244

[18] Responsa Yehuda Ya’aleh 1, Y.D. 258

[19] Responsa Daat Kohen 140

[20] Nefesh HaRav, p.243

[21] https://www.theyeshivaworld.com/news/headlines-breaking-stories/140162/rabbi-tendler-calls-metzitzah-a-prefabricated-lie.html

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