Halacha

הלכה א
הַזָּב וְהַזָּבָה וְהַנִּדָּה וְהַיּוֹלֶדֶת לְעוֹלָם הֵם בְּטֻמְאָתָן וּמְטַמְּאִין אָדָם וְכֵלִים וּמִשְׁכָּב וּמֶרְכָּב עַד שֶׁיִּטְבּוֹלוּ. אֲפִלּוּ נִתְאַחֲרוּ כַּמָּה שָׁנִים בְּלֹא רְאִיַּת טֻמְאָה וְלֹא טָבְלוּ הֲרֵי הֵן בְּטֻמְאָתָן:
כסף משנה
1.
A zav, a zavah, a nidah, and a woman after childbirth remain impure and impart impurity to humans, articles, and articles on which one sits or lies until they immerse. Even if they remained several years without an impure emission, but did not immerse, they remain impure.

הלכה ב
יוֹלֶדֶת שֶׁלֹּא טָבְלָה אַחַר שִׁבְעָה לְזָכָר וְאַרְבָּעָה עָשָׂר לִנְקֵבָה כָּל דָּם שֶׁתִּרְאֶה אַף עַל פִּי שֶׁהוּא בְּתוֹךְ יְמֵי טֹהַר הֲרֵי הוּא כְּדַם הַנִּדּוֹת וּמְטַמֵּא לַח וְיָבֵשׁ. לֹא תָּלָה הַכָּתוּב בְּיָמִים בִּלְבַד אֶלָּא בְּיָמִים וּטְבִילָה:
כסף משנה
2.
When a woman after childbirth does not immerse after the seven days of impurity obligated after the birth of a male child and the fourteen days obligated after the birth of a female child, any blood that will be discharged afterwards even though it is discharged during her days of purity, is like the blood of a nidah and imparts impurity whether it is moist or dry. Scripture did not make the matter dependent on days alone, but on days and immersion.

הלכה ג
יוֹלֶדֶת שֶׁיָּרְדָה לִטְבּל מִטֻּמְאָה לְטָהֳרָה וְנֶעֱקַר מִמֶּנָּה דָּם בִּירִידָתָהּ וְיָצָא חוּץ לְבֵין הַשִּׁנַּיִם הֲרֵי זוֹ טְמֵאָה וְאֵין הַטְּבִילָה מוֹעֶלֶת לְדָם זֶה וְאַף עַל פִּי שֶׁעֲדַיִן הִיא בִּבְשָׂרָהּ. וְאִם נֶעֱקַר מִמֶּנָּה בַּעֲלִיָּתָהּ מִן הַמִּקְוֶה הֲרֵי זוֹ טְהוֹרָה מִפְּנֵי שֶׁהוּא דַּם טֹהַר. וְהַטְּבִילָה מוֹעֶלֶת לְכָל הַדָּם הַמֻּבְלָע בָּאֵיבָרִים וּמְשִׂימָה אוֹתוֹ דַּם טֹהַר:
כסף משנה
3.
When a woman who gave birth descended to immerse herself to make the transition from impurity to purity and she discharged blood as she was descending and emerged from the inner space of her uterus, it is impure. Immersion has no effect on this blood even though it is still within her body. If she discharges it as she ascends from immersion in the mikveh, it is pure. For it is "pure blood" and the immersion is effective with regard to all the blood that is within her body and causes it to be considered as "pure blood."

הלכה ד
יוֹלֶדֶת שֶׁטָּבְלָה אַחַר שִׁבְעָה שֶׁל זָכָר וְאַרְבָּעָה עָשָׂר שֶׁל נְקֵבָה אוֹ אַחַר סְפִירַת שִׁבְעָה יָמִים נְקִיִּים אִם הָיְתָה יוֹלֶדֶת בְּזוֹב הֲרֵי הִיא בְּכָל יְמֵי טֹהַר שֶׁלָּהּ כְּטָמֵא שֶׁטָּבַל וַעֲדַיִן לֹא הֶעֱרִיב שִׁמְשׁוֹ וַהֲרֵי הִיא טְבוּלַת יוֹם בְּכָל אוֹתָן הַיָּמִים. וְאֵינָהּ צְרִיכָה טְבִילָה אַחֶרֶת בְּסוֹף יְמֵי טֹהַר אֶלָּא בְּמִשְׁלָם הַיָּמִים הֲרֵי הִיא כִּטְבוּל יוֹם שֶׁהֶעֱרִיב שִׁמְשׁוֹ. בַּמֶּה דְּבָרִים אֲמוּרִים שֶׁהִיא כִּטְבוּל יוֹם לְעִנְיַן תְּרוּמָה וּמַעֲשֵׂר. אֲבָל לְקָדָשִׁים הֲרֵי הִיא כְּרִאשׁוֹן לְטֻמְאָה שֶׁעֲדַיִן לֹא טָבַל אֶלָּא כְּמִי שֶׁנָּגַע בְּנִדָּה אוֹ בִּטְמֵא מֵת שֶׁעֲדַיִן לֹא טָבַל וְכַיּוֹצֵא בָּהֶן. נִמְצֵאתָ אַתָּה לָמֵד שֶׁהַיּוֹלֶדֶת בְּתוֹךְ יְמֵי טֹהַר אוֹכֶלֶת בְּמַעֲשֵׂר וּפוֹסֶלֶת אֶת הַתְּרוּמָה כִּטְבוּל יוֹם כְּמוֹ שֶׁיִּתְבָּאֵר. וְאִם נָפַל מֵרֻקָּהּ וּמִדַּם טָהֳרָתָהּ עַל כִּכָּר שֶׁל תְּרוּמָה הֲרֵי הוּא בְּטָהֳרָתוֹ שֶׁמַּשְׁקֵה טְבוּל יוֹם טָהוֹר כְּמוֹ שֶׁיִּתְבָּאֵר. וּמְטַמְּאָה אֶת הַקָּדָשִׁים כִּוְלַד הַטֻּמְאוֹת עַד שֶׁתַּשְׁלִים יְמֵי טֹהַר וְתִהְיֶה טְהוֹרָה לַכּל. וְיֵרָאֶה לִי שֶׁמֵּאַחַר שֶׁהִיא מְטַמְּאָה אֶת הַקֹּדֶשׁ שֶׁהִיא צְרִיכָה טְבִילָה אַחֶרֶת בַּסּוֹף וְאַחַר כָּךְ תִגַּע בַּקֹּדֶשׁ אַף עַל פִּי שֶׁאֵינָהּ צְרִיכָה טְבִילָה אַחֶרֶת לַאֲכִילַת הַתְּרוּמָה:
כסף משנה
4.
When a woman after childbirth immersed after the seven impure days that follow the birth of a male, after the fourteen impure days that follow the birth of a female, or after counting seven spotless days if she gave birth in a state of zivah, throughout her days of purity, she is considered as an impure person who immersed but nightfall has not arrived. She is not required to undergo another immersion at the conclusion of her days of purity. Instead, when those days are completed, she is like a person who immersed in the mikveh and the day passed.
In which contexts is she considered as a person who has immersed that day? With regard to terumah and the second tithe. But with regard to sacrificial food, she is like a person who is a derivative of impurity who did not immerse. She is like a person who touched a nidah or a person who is impure due to contact with a corpse who has not yet immersed, or the like. Thus it can be concluded that a woman in the midst of her days of purity may partake of the second tithe and disqualifies terumah like a person who has immersed that day does, as will be explained.
If some of her saliva or her pure blood fell on a loaf of bread that was terumah, the loaf remains pure. For fluids coming from a person who immersed that day are pure, as will be explained. Such fluids do, however, impart impurity to sacrificial foods as a derivative of impurity would until her days of purity are completed and she is pure in all respects. It appears to me that since she imparts impurity to sacrificial foods during these days of purity, she must immerse herself at the end of her days of purity and only then may she touch sacrificial food. This applies even though she does not require another immersion to partake of terumah.

הלכה ה
יוֹלֶדֶת שֶׁהִיא מְצֹרַעַת וְטָבְלָה אַחַר שִׁבְעָה שֶׁל זָכָר אוֹ אַרְבָּעָה עָשָׂר שֶׁל נְקֵבָה הֲרֵי דַּם טֹהַר שֶׁלָּהּ טָמֵא כְּרֻקָּהּ וּכְמֵימֵי רַגְלֶיהָ. וְכֻלָּן כְּמַשְׁקִין טְמֵאִין שֶׁכָּל הַמַּשְׁקִין הַטְּמֵאִין הַיּוֹצְאִין מֵהֶן כְּמַשְׁקִין שֶׁהֵן נוֹגְעִין בָּהֶן. חוּץ מִזָּב וְכַיּוֹצֵא בּוֹ. שֶׁהֲרֵי שְׁלֹשָׁה מַשְׁקִין הַיּוֹצְאִין מִמֶּנּוּ אֲבוֹת טֻמְאוֹת כְּמוֹ שֶׁבֵּאַרְנוּ:
כסף משנה
5.
When a woman who gave birth and who is afflicted by tzara'at immersed herself after the seven days of impurity required after giving birth to a male or the fourteen days required after a female, her "pure blood" is impure like her saliva and her urine. They are all considered as impure fluids, for all fluids that become impure that are discharged from impure people are like liquids that they touch with the exception of a zav and the like. For the three fluids they discharge are sources of ritual impurity, as we explained.

הלכה ו
זָבָה קְטַנָּה שֶׁטָּבְלָה בַּיּוֹם הַשִּׁמּוּר שֶׁלָּהּ אַחַר הָנֵץ כְּמוֹ שֶׁבֵּאַרְנוּ בְּעִנְיַן אִסּוּר נִדָּה הֲרֵי מַגָּעָהּ וּבְעִילָתָהּ תְּלוּיִים. אִם נִגְמַר הַיּוֹם וְלֹא רָאֲתָה כָּל שֶׁנָּגְעָה בּוֹ טָהוֹר וּבוֹעֲלָהּ טָהוֹר וּפָטוּר. וְאִם רָאֲתָה דָּם אַחַר שֶׁטָּבְלָה כָּל טָהֳרוֹת שֶׁעָשְׂתָה טְמֵאוֹת וְעוֹשָׂת מִשְׁכָּב וּמֶרְכָּב וּבוֹעֲלָהּ חַיָּב חַטָּאת. טָבְלָה בְּלֵיל הַשִּׁמּוּר קֹדֶם שֶׁיַּעֲלֶה עַמּוּד הַשַּׁחַר הֲרֵי זוֹ כְּמִי שֶׁלֹּא טָבְלָה וַעֲדַיִן עוֹשָׂת מֶרְכָּב וּמוֹשָׁב:
כסף משנה
6.
When a minor zavah immerses on the day she is watching after sunrise, the status of the articles she touches and a man with whom she is intimate is indefinite, as we explained with regard to the prohibitions of nidah. If she completes the day without experiencing further uterine bleeding, anything she touches is pure and one who is intimate with her is pure and he is exempt. If she experiences uterine bleeding after she immerses, any pure objects that she touched are impure, the laws concerning the impurity imparted by a zav to an article on which one lies or rides apply and a man who is intimate with her is liable for a sin-offering.
If she immersed herself before dawn during the night before the day on which she should be cautious, it is as if she never immersed and the laws concerning the impurity imparted by a zav to an article on which one lies or rides apply.

הלכה ז
הָרוֹאָה דָּם בְּיוֹם אַחַד עָשָׂר וְטָבְלָה לְעֶרֶב לֵיל שְׁנֵים עָשָׂר הֲרֵי זוֹ מְטַמְּאָה מִשְׁכָּב וּמוֹשָׁב. אַף עַל פִּי שֶׁאֵינָהּ רְאוּיָה לִהְיוֹת זָבָה גְּדוֹלָה כְּמוֹ שֶׁבֵּאַרְנוּ בְּעִנְיַן אִסּוּר נִדָּה:
כסף משנה
7.
When a woman experiences uterine bleeding on the eleventh day of zivah. and immersed herself in the evening, on the night of the twelfth, the laws concerning the impurity imparted by a zav to an article on which one lies or rides apply even though she is not fit to become a major zavah, as we explained with regard to the prohibitions of nidah.

הלכה ח
טָבְלָה בְּיוֹם שְׁנֵים עָשָׂר אַחַר הָנֵץ הַחַמָּה אַף עַל פִּי שֶׁאֲסוּרָה לְשַׁמֵּשׁ [עַד] לָעֶרֶב אִם שִׁמְּשָׁה בּוֹעֲלָהּ טָהוֹר וּמִשְׁכָּבָהּ וּמֶרְכָּבָהּ טְהוֹרִין אַף עַל פִּי שֶׁרָאֲתָה דָּם בְּיוֹם שְׁנֵים עָשָׂר אַחַר הַטְּבִילָה. מִפְּנֵי שֶׁהוּא תְּחִלַּת נִדָּה כְּמוֹ שֶׁבֵּאַרְנוּ שָׁם בְּאִסּוּר נִדָּה וְאֵינוֹ מִצְטָרֵף לְיוֹם אַחַד עָשָׂר לְפִיכָךְ אֵינָהּ צְרִיכָה לִשְׁמֹר יוֹם שְׁנֵים עָשָׂר אֶלָּא טוֹבֶלֶת וְעוֹסֶקֶת בְּטָהֳרוֹת. אֲבָל הָרוֹאָה דָּם בַּעֲשִׂירִי טוֹבֶלֶת בְּיוֹם אַחַד עָשָׂר וּמְשַׁמֶּרֶת אוֹתוֹ שֶׁאִם תִּרְאֶה בּוֹ דָּם אַחַר טְבִילָה נִטְמְאוּ כָּל טָהֳרוֹת שֶׁעָשְׂתָה וְנִטְמָא בּוֹעֲלָהּ אַף עַל פִּי שֶׁאֵינָהּ רְאוּיָה לִהְיוֹת זָבָה גְּדוֹלָה כְּמוֹ שֶׁבֵּאַרְנוּ בְּעִנְיַן נִדָּה:
כסף משנה
8.
If she immersed on the twelfth day after sunrise, although she is forbidden to engage in intimacy until the evening, if she was intimate, the man with whom she was intimate is pure and articles on which one lies or rides that she touches are pure even if she experiences uterine bleeding on the twelfth day after immersion. The rationale is that this day is the beginning of the days of nidah, as we explained with regard to the prohibitions of nidah. The twelfth day is never joined to the eleventh day. Therefore even if she experiences bleeding on the eleventh day, she need not be cautious regarding the twelfth day. Instead, she may immerse herself and touch articles that are ritually pure.
If, by contrast, she experiences uterine bleeding on the tenth day, she should immerse herself on the eleventh day and be cautious with regard to it. For if she experiences uterine bleeding after immersing herself all the pure articles she touches become impure. Similarly, a man with whom she engages in relations becomes impure, even though she will never become a major zavah as a result of this bleeding, as we explained with regard to the prohibitions of nidah.

הלכה ט
זָב וְזָבָה גְּדוֹלָה שֶׁטָּבְלוּ בְּיוֹם שְׁבִיעִי שֶׁלָּהֶן כְּמוֹ שֶׁבֵּאַרְנוּ לֹא יִתְעַסְּקוּ בְּטָהֳרוֹת עַד לָעֶרֶב שֶׁמָּא יִרְאוּ טֻמְאָה וְיִסְּתְּרוּ שִׁבְעַת יְמֵי הַסְּפִירָה וְנִמְצָא אוֹתָן הַטָּהֳרוֹת טְמֵאוֹת לְמַפְרֵעַ. אַף עַל פִּי שֶׁהֵן עוֹשִׂין מִשְׁכָּב וּמוֹשָׁב לְמַפְרֵעַ אֵין מְטַמְּאִין כְּלֵי חֶרֶס בְּהֶסֵּט מֵאַחַר שֶׁטָּבְלוּ אַף עַל פִּי שֶׁחָזְרוּ וְרָאוּ טֻמְאָה וְסָתְרוּ הַכּל. וְכָל כְּלִי חֶרֶס שֶׁהֱסִיטוּ עַד שֶׁלֹּא רָאוּ טָהוֹר:
כסף משנה
9.
When a zav and a major zavah immerse on their seventh spotless day as we explained, they should not touch articles that are ritually pure until the evening, lest they experience an impure discharge that day. In such an instance, that would disqualify the seven days which were counted and retroactively, the pure articles would become impure. Although the laws concerning the impurity imparted by a zav to an article on which one lies or rides apply retroactively, they do not retroactively impart impurity to an earthenware utensil that they moved after they immersed even though they experienced an impure discharge after immersing and disqualified all the days that they had counted. Nevertheless, any earthenware utensil that they touched until they experienced the discharge is pure.

טהרה הלכות מטמאי משכב ומושב פרק ה
Taharah Metamei Mishkav and Moshav Chapter 5