menu
small logo

Back

Niddah

Daf 54a

יְמֵי לֵידָה שֶׁאֵינָהּ רוֹאָה בָּהֶן, מַהוּ שֶׁיַּעֲלוּ לִסְפִירַת זִיבָתָהּ?

What is the halakha in the case of a woman who gave birth when she was a zava ? There are seven days of impurity following the birth of a son and fourteen days of impurity following the birth of a daughter, during which the mother is impure even if she did not experience bleeding. With regard to those days during this period on which she does not see blood, are they reckoned in the counting of her seven clean days required to become purified from the status of ziva ?

אָמַר רַב כָּהֲנָא: תָּא שְׁמַע, רָאֲתָה שְׁנַיִם, וְלַשְּׁלִישִׁי הִפִּילָה, וְאֵינָהּ יוֹדַעַת מַה הִפִּילָה

Rav Kahana says: Come and hear a baraita : A woman saw blood on two consecutive days during the period of ziva , and on the third day she miscarried, but she does not know what she miscarried, i.e., whether it was a stillborn human fetus for which a woman contracts the impurity of childbirth, or whether she discharged an amorphous piece of tissue. In addition, she does not know whether she emitted blood during the miscarriage.

RASHI

רביע ימיה מתוך כ"ח שבעה ימים שאחר שבעה הטמאים של נדות היא משמשת ובשבעה השלישיים תהא זבה ובשבעה האחרונים הן ימי הספירה הרי כ"ח וביום כ"ט תהא תחלת נדה ונמצאת משמשת רביע ימיה ולהכי נקט כ"ח מפני שתחלת נדותה של זו מכ"ח לכ"ח:

הֲרֵי זוֹ סְפֵק זִיבָה סְפֵק לֵידָה.

In such a case, it is uncertain whether she has the status of one who experienced ziva or whether she has the status of a woman who gave birth. If she gave birth to a fetus and did not emit blood, she is a woman after childbirth but not a zava . If the discharge was an amorphous piece of tissue and she saw blood, she is a zava . If it was a human fetus and she saw blood, she is one who gives birth as a zava . Finally, if she did not emit blood and it was a discharge of an amorphous piece of tissue, she is not obligated to bring an offering at all.

RASHI

ט"ו יום מתוך מ"ח כגון ח' הראשונים השמיני ימי זיבה ומשמונה השניים תשמור יום לשמיני שלפניו ותשמש שבעה הרי ט"ז שעברו עליה ונשארו ב' לבא מימי זיבה ושמונה השלישיים שנים מהן ימי זוב והששה תחילת נדתה ושמונה הרביעיים שהן טהורים הראשונים ישלים ז' ימי נדה והשבעה תשמש ועכשיו נותרו ד' ימים מימי זיבה שמונה החמשיים הרי היא זבה משלשה ראשונים וח' שלאחריהן שבעה לספירה ושמיני לתשמיש הרי ט"ו יום מתוך מ"ח וביום מ"ט כשתראה תהא תחלת נדה ותחזור למנין שאמרנו:

מְבִיאָה קָרְבָּן וְאֵינוֹ נֶאֱכָל, וִימֵי לֵידָתָהּ שֶׁאֵין רוֹאָה בָּהֶן – עוֹלִין לָהּ לִסְפִירַת זִיבָתָהּ.

Consequently, she brings an offering but it is not eaten by the priests, as it is uncertain whether it is an offering of ziva or an offering for her childbirth, or whether it is non-sacred. And the days of impurity following this uncertain birth, on which she does not see blood, are reckoned in the counting of her seven clean days required to become purified from the status of ziva . This resolves the dilemma raised by the Sages.

RASHI

ארביסר הוו קסבר האי דמותיב שהאשה הזאת לא תשמש יום מ"ח לפי שהשמונה החמשיים שנעשית בהן זבה אין מהן אלא ד' מימי זיבה וד' האחרונים מימי נדה הן ומיהו תחלת נדה לא הוי כל זמן שלא ספרה ולא טהרה מזובה אבל להכי מהניא הך ראייה ד' האחרונים הראויין לנדות שכשיבאו שמונה טהורין שאחריהם לא יעלו שלשה הראשונים לימי הספירה לפי שהן השלמת ימי נדה וימי נדתה שאינה רואה בהן אין עולין לספירת זיבתה הלכך אין כאן אלא חמשה לספירה וכשתראה יום מ"ט סותרת וכן כל ח' השביעיים (יום) ועד שיגיע יום ס"ג לא ישלימו ימי ספירתה:

TOSAFOT

אלא ש"מ עולין ש"מ וטעמא דרב הונא בריה דרב יהושע אע"ג דהוי ספק ספקא מ"מ אי בעלמא אין עולין הכא נמי הוה לן למגזר אטו בעלמא:

אָמַר רַב פַּפָּא: שָׁאנֵי הָתָם, כֵּיוָן דְּאִיכָּא לְמֵימַר יוֹלֶדֶת זָכָר הִיא, וְכָל הָנֵי שִׁבְעָה יְתֵירֵי דְּקָיָהֲבִינַן לָהּ – סָלְקִי לָהּ לִסְפִירַת זִיבָתָהּ.

Rav Pappa says that this does not resolve the dilemma, as it is different there, since it can be said that she is a woman who gave birth to a male, and it is only for that reason that all of these additional seven days that we give her due to the concern that she might have given birth to a female, which would render her impure for fourteen days, are reckoned in the counting of her seven clean days of ziva . But if it was certain that she gave birth to a female, those days after the birth would not count toward her period of ziva .

אֲמַר לֵיהּ רַב הוּנָא בְּרֵיהּ דְּרַב יְהוֹשֻׁעַ לְרַב פַּפָּא: בְּיוֹלֶדֶת זָכָר – אִיכָּא לְסַפּוּקֵי, בְּיוֹלֶדֶת נְקֵבָה – לֵיכָּא לְסַפּוּקֵי? אֶלָּא לָאו שְׁמַע מִינָּהּ: עוֹלִין, שְׁמַע מִינָּהּ.

Rav Huna, son of Rav Yehoshua, said to Rav Pappa: Is there uncertainty that perhaps she is a woman who gave birth to a male, but there is no uncertainty that she might be a woman who gave birth to a female? In fact, both possibilities must be taken into account. And yet, despite the fact that she might have given birth to a female, these seven days are included in the counting of her seven clean days. Rather, isn’t it correct to conclude from it that such days are reckoned in the counting? The Gemara comments: Indeed, conclude from the baraita that these days do count.

RASHI

ימי לידתה כגון ילדה בזוב ופסקה מיד:

TOSAFOT

וכן למאה וכן לאלף ימי שמושה בימי זיבתה דמאחר ז' ימי נדה כל הימים שתראה אפילו מאה או אלף מקרו ימי זיבתה עד שתספור ז' נקיים:

תִּשְׁעָה יָמִים טְמֵאִין וְתִשְׁעָה יָמִים טְהוֹרִין – מְשַׁמֶּשֶׁת שְׁמוֹנָה יָמִים מִתּוֹךְ שְׁמוֹנָה עָשָׂר.

The Gemara concludes its citation of the baraita : In the case of a woman whose set pattern is that nine days she is impure, i.e., experiences bleeding, and nine days she is pure, she may engage in intercourse with her husband during eight days out of eighteen. The last two days of the nine with blood are part of her ziva period, after which she must observe one clean day, leaving her with eight days when she may engage in intercourse before the cycle begins again.

RASHI

הכי גרסינן ראתה שנים ראתה שני ימים בשופי בתוך י"א שבין נדה לנדה:

עֲשָׂרָה יָמִים טְמֵאִין וַעֲשָׂרָה יָמִים טְהוֹרִים – יְמֵי שִׁמּוּשָׁהּ כִּימֵי זִיבָתָהּ. וְכֵן לְמֵאָה וְכֵן לְאֶלֶף. הדרן עלך בא סימן

In the case of a woman whose set pattern is that ten days she is impure and ten days she is pure, the number of days of her being permitted to engage in intercourse with her husband is equivalent to the number of days of her experiencing the flow of ziva . In the first seven days she is a menstruating woman, followed by three days of blood that render her a zava . She must count seven of the ten days without blood to be purified from her ziva , which leaves her three days in which she may engage in intercourse, exactly the same as the three days of ziva on which she saw blood. And so too, the same applies in the case of one hundred days, as she experiences bleeding of ziva for ninety-three days, and is subsequently permitted to her husband for ninety-three days, and so too in the case of one thousand days.

RASHI

ספק לידה ספק זיבה שמא לידה שמא זיבה שמא לא זו ולא זו אם ולד הוא ולא ראתה בפתיחת הקבר הרי היא לידה ולא זיבה ואם אינו ולד וראתה דם בפתיחת הקבר הרי היא זיבה ואין כאן לידה ואם ולד הוא וראתה דם בלידה הרי זו יולדת בזוב ואם נפתח קבר בלא דם ואינו ולד אין כאן לא זו ולא זו הלכך ספק הוא ונטיל עליה חומר לידה לטמא שבועיים אפילו לא תראה וחומר זיבה שכל זמן שלא תפסוק ז' נקיים לא תטהר ומביאה קרבן ואינו נאכל שמא אין כאן לא לידה ולא זיבה:

SUMMARY

A woman is not rendered impure as a menstruating woman by Torah law when she discovers blood on her body or a stain on her garment. This is derived from the verse: “And if a woman has an issue, and her issue in her flesh is blood” (Leviticus 15:19). Two important halakhot are derived from the verse with regard to this matter. First, she becomes impure when she sees an actual discharge of blood, not merely blood on her body or a stain on her garment. Second, she becomes impure only when she has an accompanying physical sensation that she emitted blood from her uterus. This is the halakha only by Torah law, as the Sages decreed impurity on a woman who discovers a stain on her body or on her garment. They instituted that stains render her impure so that people would not treat the impurity of her blood lightly. This is related to the fact that there are two basic ramifications to an emission of blood from the uterus. First, it renders her impure as a menstruating woman. Second, the blood itself is ritually impure and renders one who touches it impure until the evening. Although by discovering a stain a woman is not rendered impure as a menstruating woman by Torah law, nevertheless, the Sages decreed that she is impure so that people would not be lenient with regard to the impurity of the blood itself. In addition, the Sages were concerned about the possibility that a woman might have actually sensed the emission of the blood that produced this stain, but didn’t realize it, which would mean that she is in fact impure by Torah law. The Sages disagreed with regard to the case of a woman who discovered a stain the size of at least three split beans on a garment that she wore for three days during the period on which she can assume the status of a zava. Some rule that she is considered a zava in all respects, due to the concern that this stain might consist of three stains from three days, each of which is the requisite measure of at least one split bean. Others maintain that there is no concern about this possibility. All agree that a woman who discovered on three different garments three different stains, each the requisite size of at least one split bean, on three different days of the days of ziva, is rendered a greater zava. The chapter first continued the previous chapter’s recounting of the stages in the maturation of a young woman. This consists of an analysis of the appearance of the lower sign, two pubic hairs, as well as the upper sign, the development of the breasts. The assumption according to one opinion among the tanna’im is that the lower sign invariably appears first. The status of a young woman whose upper sign appeared but did not yet develop the lower sign is the subject of a dispute among the tanna’im. Much of the rest of the chapter does not deal with the halakhot of a menstruating woman at all, but with tangential issues. Those matters are cited here due to the structural similarity between their formulation and a ruling stated with regard to the upper and lower signs, where there are two asymmetrical halakhot.

INTRO

This is the law of him that has an issue, and of him from whom the semen is emitted, so that he is impure thereby. And of her who experiences the flow of her menstrual impurity, and of one who emits his issue, in the case of a male or a female, and of him who lies with her who is impure. (Leviticus 15:32–33)

The verse “And if a woman has an issue, and her issue in her flesh is blood” deals with the impurity of menstruation. It teaches that a woman is rendered impure by a discharge of blood from the uterus. From that point onward she has the status of a primary source of ritual impurity; she renders vessels impure by contact with them, and renders people impure if they come into contact with her or carry her. In addition to the woman herself, her blood transmits impurity to anyone who touches or carries it. This is derived from the phrase “and of her who experiences the flow of her menstrual impurity,” which compares the status of the menstrual flow to the status of the menstruating woman. Exactly how menstrual blood transmits impurity requires clarification. Is it a source of impurity only when it is in a liquid state, similar to substances emitted by a zav, such as his saliva and semen, which transmit impurity only when moist? Or does dry menstrual blood also transmit impurity? If it is established that dry menstrual blood also transmits impurity, it is necessary to clarify whether this applies only to blood that was initially moist or even to a menstrual discharge that was dry from the outset. Similar to the dry blood of a menstruating woman, the dried-out flesh of a corpse also imparts ritual impurity. It is necessary to define what constitutes dried-out flesh, as at some point it is no longer called by this name and ceases to transmit impurity. Apropos the discussion with regard to the blood of a menstruating woman and the flesh of a corpse, the chapter discusses whether other sources of impurity transmit impurity even when they are dry, e.g., the various impure emissions of a zav, an animal carcass, and semen. The previous and following chapters discuss the halakhot of blood stains found on a woman’s garments. These stains do not render her impure by Torah law, but they render her impure by rabbinic law. A woman who finds a blood stain on her garments is rendered impure just as in the case of a woman who experienced a discharge of uterine blood. Since the blood stain might have been caused some time ago the woman is rendered impure retroactively, and any pure items she touched previously are rendered impure. This leads to the question of how far back in time the woman is rendered impure retroactively. This decree of the Sages with regard to blood stains applies only to stains of Jewish women. Although the Sages decreed that gentiles have the status of zavim in all regards, they did not apply the status of impurity to the blood stains of gentile women. Consequently, concerning the status of blood stains that come from places inhabited by both Jews and gentiles, it is necessary to establish whether these stains are ritually pure or impure.

מתני׳ דַּם הַנִּדָּה וּבְשַׂר הַמֵּת – מְטַמְּאִין לַחִין וּמְטַמְּאִין יְבֵשִׁין. אֲבָל הַזּוֹב, וְהַנִּיעַ, וְהָרוֹק, וְהַשֶּׁרֶץ, וְהַנְּבֵלָה, וְהַשִּׁכְבַת זֶרַע – מְטַמְּאִין לַחִין וְאֵין מְטַמְּאִין יְבֵשִׁין. וְאִם יְכוֹלִין לְהַשְׁרוֹת וְלַחֲזוֹר לִכְמוֹת שֶׁהֵן – מְטַמְּאִין לַחִין וּמְטַמְּאִין יְבֵשִׁין.

The blood of a menstruating woman and the flesh of a corpse transmit impurity by contact and by carrying when they are moist, and likewise transmit impurity when they are dry. But with regard to the gonorrhea-like discharge of a zav [ ziva ], and the mucus and the saliva of a zav , and the carcass of a creeping animal, and an animal carcass, and semen, all transmit impurity when they are moist but do not transmit impurity when they are dry. And if one could soak those dry substances in water and thereby restore them to their previous state, they transmit impurity when moist and transmit impurity when dry.

RASHI

וימי לידתה שאין רואה בהן עולין כו' ואע"ג דאיכא לספוקי ביולדת בזוב ויש כאן לידה וזיבה:

וְכַמָּה הִיא שְׁרִיָּיתָן? בְּפוֹשְׁרִין מֵעֵת לְעֵת. רַבִּי יוֹסֵי אוֹמֵר: בְּשַׂר הַמֵּת יָבֵשׁ, וְאֵינוֹ יָכוֹל לְהִשָּׁרוֹת וְלַחֲזוֹר לִכְמוֹת שֶׁהָיָה – טָהוֹר.

The mishna asks: And how long is the process of soaking these substances that determines whether they can be restored to their previous state? This is referring to soaking them in lukewarm water for a twenty-four-hour period. Rabbi Yosei says: With regard to the flesh of a corpse that is dry and cannot be soaked to restore it to its previous state, it is ritually pure, in the sense that an olive-bulk of the flesh does not transmit impurity imparted by a corpse. But a ladleful of the flesh transmits the impurity of the decayed flesh of a corpse.

RASHI

משום דאיכא למימר כו' אבל אי הוה פשיטא לן דיולדת נקבה היא לא סלקי לה:

TOSAFOT

דם הנדה מנא הני מילי. לרבא דאמר בפ' בנות כותים (לעיל נדה לה.) לאחרים גורם טומאה לעצמו לא כ"ש ולית ליה דשעיר המשתלח יוכיח הכא לא צריך קרא ומיהו לדם נדה של מצורעת אצטריך שפיר קרא דהדם אינו גורם טומאה ולקמן דמצריך קרא לטומאת זובו במגע ובמשא ולא יליף מדם הנדה דהכא משום דאיכא למפרך מה לדם הנדה שכן מטמא באונס ואם תאמר וכיון דלא ילפינן מהכא אמאי אצטריך לקמן קרא למעוטי זוב יבש מהיכא תיתי לטמא ויש לומר כיון דהשוה הכתוב דם נדה וזוב לטומאה ממילא ילפינן מהדדי דגילוי מילתא בעלמא הוא:

גמ׳ מְנָא הָנֵי מִילֵּי? אָמַר חִזְקִיָּה, דַּאֲמַר קְרָא ״וְהַדָּוָה בְּנִדָּתָהּ״, מַדְוֶה כְּמוֹתָהּ, מַה הִיא מְטַמְּאָה, אַף מַדְוֶה מְטַמְּאָה.

The mishna teaches that the blood of a menstruating woman transmits impurity by contact and by carrying both when moist and when dry. The Gemara asks: From where are these matters derived? Ḥizkiyya says: They are derived from a verse, as the verse states with regard to a menstruating woman: “This is the law of him that has an issue… And of her who experiences the flow of her menstrual impurity” (Leviticus 15:32–33). The verse compares the status of the menstrual flow to that of the menstruating woman. This teaches that the status of the menstrual flow is like the status of the woman herself: Just as she transmits impurity by contact and by carrying, so too, the menstrual flow transmits impurity by contact and by carrying.

אַשְׁכַּחַן לַח, יָבֵשׁ מְנָלַן? אָמַר רַבִּי יִצְחָק: אֲמַר קְרָא ״יִהְיֶה״ – בַּהֲוָיָתוֹ יְהֵא.

The Gemara asks: We found a source for the impurity of the menstrual blood when it is moist, since it is called the menstrual flow; from where do we derive that dry menstrual blood also transmits impurity? Rabbi Yitzḥak says that the verse states with regard to menstrual impurity: “And if a woman should have an issue, and her issue in her flesh shall be blood, she shall be in her impurity seven days, and whoever touches her shall be impure until the evening” (Leviticus 15:19). The term “shall be” indicates that the blood shall remain in its impure status even once it is dry.

RASHI

ט' ימים טמאין תרי מינייהו זיבה וכי חזיא טהורין חד מינייהו הוי שימור ושמונה לתשמיש וביום י"ט הויא תחלת נדה וכן לעולם לא תהא זבה:

TOSAFOT

ותו הא דתנן המפלת כו' תימה דהיינו ההיא קושיא גופיה וי"ל דה"ק וכ"ת דאין הכי נמי דיבש מעיקרא טהור והתנן המפלת כו' אי נמי י"ל ותו יבש משונה כמין יבחושין או כמין קליפה מנלן:

וְאֵימָא: הָנֵי מִילֵּי בְּלַח וְנַעֲשָׂה יָבֵשׁ, יָבֵשׁ מֵעִיקָּרוֹ מְנָלַן? וְתוּ, הָא דִּתְנַן: הַמַּפֶּלֶת כְּמִין קְלִיפָּה, כְּמִין עָפָר, כְּמִין שְׂעָרָה, כְּמִין יַבְחוּשִׁין אֲדוּמִּים – תַּטִּיל לַמַּיִם, אִם נִמּוֹחוּ טָמֵא מְנָלַן? ״יִהְיֶה״ רִבּוּיָא הוּא.

The Gemara objects: But one may say that this statement applies only to blood that was initially moist and subsequently became dry, as it retains its initial status. With regard to blood that was dry at the outset, from where do we derive that it too transmits impurity? And furthermore, this inference does not provide a source for that which we learned in a mishna (21a): In the case of a woman who discharges an item whose shape is similar to a type of shell, similar to a type of soil, similar to a type of hair, or similar to a type of mosquito, if such items are red, she should cast them into water to ascertain their nature. If they dissolved, it is blood, and the woman is impure. From where do we derive that even this type of blood is impure? The Gemara explains: The term “shall be” is an amplification, indicating that menstrual blood in all these forms is impure.

RASHI

ימי שמושה כימי זיבתה דמעשרה טמאין הוו ז' נדה וג' זיבה ומעשרה טהורין ז' לספירה וג' לתשמיש הרי ימי שימוש בימי זיבה:

וכן למאה טמאין ז' ימי נדה וכולהו ימי זיבה ומאה טהורין ז' לספירה וכולהו לתשמיש וכן לאלף:

אִי מַה הִיא עוֹשָׂה מִשְׁכָּב וּמוֹשָׁב לְטַמֵּא אָדָם וּלְטַמֵּא בְּגָדִים, אַף דָּמָהּ נַמִי עוֹשֶׂה מִשְׁכָּב וּמוֹשָׁב לְטַמֵּא אָדָם וּלְטַמֵּא בְּגָדִים? אַטּוּ דָּמָהּ בַּר מִשְׁכָּב וּמוֹשָׁב הוּא?

The Gemara objects: If so, one can likewise infer the following: Just as she, a menstruating woman, renders an item designated for lying or sitting impure to the extent that it transmits impurity to a person and to the extent that that person transmits impurity to his garments, despite the fact that the garments did not come into contact with the couch, so too, her blood also renders items designated for lying or sitting impure to the extent that they transmit impurity to a person and to the extent that he transmits impurity to his garments, in the manner of a primary source of ritual impurity. The Gemara replies: Is that to say that the concepts of lying and sitting apply to her menstrual blood? These categories of impurity are limited to people.

TOSAFOT

יכול תהא אבן מנוגעת כו' אבן מנוגעת שמטמאה בביאה כו' וא"ת מת יוכיח שמטמא בביאה ואינו עושה משכב ומושב ועוד מצורע גופיה מפרש ר"ת בריש אלו דברים (פסחים דף סז:) דלא עביד משכב ומושב אלא לטמא אוכלין ומשקין ויש לומר דמקרא דהכא ממעטינן להו הזב ולא המצורע ולא המת:

וּלְטַעֲמִיךְ, אֶבֶן מְנוּגַּעַת בַּת מִשְׁכָּב וּמוֹשָׁב הִיא, דְּאִיצְטְרִיךְ קְרָא לְמַעוּטֵי? דְּתַנְיָא: יָכוֹל תְּהֵא אֶבֶן מְנוּגַּעַת עוֹשָׂה מִשְׁכָּב וּמוֹשָׁב לְטַמֵּא אָדָם לְטַמֵּא בְּגָדִים.

The Gemara asks: But according to your reasoning that this category of impurity is limited to people, do the concepts of lying and sitting apply to a stone afflicted with leprosy, that a verse was necessary to exclude it? As it is taught in a baraita : One might have thought that a stone afflicted with leprosy should render an item designated for lying or sitting impure to the extent that it transmits impurity to a person and to the extent that he transmits impurity to his garments.

RASHI

מתני' דם הנדה:

והניע קר"ק בלע"ז. וממעיינות הזב הן והוי אב הטומאה:

וְדִין הוּא, וּמַה זָּב שֶׁאֵינוֹ מְטַמֵּא בְּבִיאָה עוֹשֶׂה מִשְׁכָּב וּמוֹשָׁב לְטַמֵּא אָדָם לְטַמֵּא בְּגָדִים, אֶבֶן מְנוּגַּעַת שֶׁמְּטַמְּאָה בְּבִיאָה אֵינוֹ דִּין שֶׁמְּטַמְּאָה מִשְׁכָּב וּמוֹשָׁב לְטַמֵּא אָדָם לְטַמֵּא בְּגָדִים.

The baraita explains: And this ruling might be derived by logical inference: If one enters a house where there is a stone afflicted with leprosy he becomes impure, but one who enters a house together with a man who experienced a gonorrhea-like discharge [ zav ] does not become impure. One may therefore infer as follows: If a zav , who does not transmit impurity by entering a house, nevertheless renders an item designated for lying or sitting impure to the extent that it transmits impurity to a person and to the extent that that person transmits impurity to his garments, then with regard to a stone afflicted with leprosy, which does transmit impurity by entering a house, is it not logical that it renders an item designated for lying or sitting impure to the extent that it transmits impurity to a person and to the extent that he transmits impurity to the garments he is wearing?

RASHI

וכמה היא שרייתן דנימא אי הדרא בכי האי שיעורא לחין נינהו:

בפושרים מעת לעת אבל אי בעי טפי מים חמים או יותר ממעת לעת יבשין הן:

תַּלְמוּד לוֹמַר ״הַזָּב״, הַזָּב – וְלֹא אֶבֶן מְנוּגַּעַת. טַעֲמָא דְּמַעֲטֵיהּ קְרָא, הָא לָאו הָכִי מְטַמְּאָה!

The baraita concludes: Therefore, the verse states: “Every bed upon which the zav lies shall be impure, and every item upon which he sits shall be impure” (Leviticus 15:4). The term “the zav indicates that only the zav , and not a stone afflicted with leprosy, renders items designated for lying or sitting impure. The Gemara infers from the baraita : The reason a stone afflicted with leprosy does not transmit impurity to items designated for lying or sitting is that the verse excluded it, but were it not so, the stone would transmit impurity to items designated for lying or sitting, despite the fact that the concepts of lying and sitting do not apply to a stone.

RASHI

גמ' מנא הני מילי דדם נדה מטמא מגעו ומשאו:

וּמִינָּהּ, לָאו מִי אָמְרַתְּ הַזָּב – וְלֹא אֶבֶן מְנוּגַּעַת, הָכִי נַמִי אֲמַר קְרָא: ״אֲשֶׁר הִיא יוֹשֶׁבֶת עָלָיו״ – הִיא וְלֹא דָּמָהּ.

The Gemara replies that from this same derivation one can infer that menstrual blood does not render items designated for lying or sitting impure: Didn’t you say that the term “the zav ” teaches that only the zav , and not a stone afflicted with leprosy, renders items designated for lying or sitting impure? So too, a verse excludes menstrual blood from this category of impurity, as the verse states: “And he if is on the bed, or on any item upon which she sits, when he touches it, he shall be impure until the evening” (Leviticus 15:23). The term “she” indicates that she, the menstruating woman, but not her blood, transmits impurity to items designated for lying or sitting.

RASHI

אשכחן לח דדוה לח משמע כעין שהוא זב:

יהיה דם יהיה זובה: