Preparing for the Mikveh
There are five stages in the process of a woman becoming purified from her Niddah (impure) status during which she is prohibited to her husband. These stages include: (1) waiting 4 or 5 days, (2) performing a Hefsek Tahara, (3) counting the Shiva Nekiyim and checking during those days, (4) preparing for the mikveh, and (5) going to the mikveh. This page presents the various laws regarding each of these stages.
Waiting Before Doing Hefsek Tahara
- A woman who sees her period needs to wait 4 days according to Sephardim or 5 days according to Ashkenazim and then she can perform a hefsek tahara in order to begin the shiva nekiyim. According to Sephardim, these 4 days are counted from the time when she was last with her husband. Nonetheless, a woman can never count her shiva nekiyim until she did a hefsek tahara and didn’t see any blood. However, according to Ashkenazim, these 5 days are counted from the beginning of her period whether or not she was with her husband recently and even if her husband wasn’t in town.
- For example, if a woman sees blood on Shabbat, according to Ashkenazim she could do her hefsek tahara on Wednesday afternoon and according to Sephardim she could do her hefsek tahara on Tuesday afternoon. This minimum waiting period only applies if she stopped bleeding before that time, if not she can not do a hefsek tahara and needs to wait another day. If the Shiva Nekiyim continue successfully she can go to mikveh the next Wednesday night.
- The 4 or 5 days are counted according to halachic days starting at night. If a woman saw blood during sunset and nightfall a Rav should be consulted as to determine which day she can begin she 4 or 5 day waiting period.
- If a woman sees blood during the day after she, her shul, or community prayed maariv early she can count the 4 or 5 days from that day and she doesn't have to begin her count or 4 or 5 days from that night.
Exceptions to Waiting Five Days
- If a woman sees blood in the middle of shiva nekiyim she needs to start again, but she doesn’t have to wait 4 or 5 days before she can do a hefsek tahara. Rather she can do the hefsek tahara that day and then start counting the shiva nekiyim the next day.
- A bride the first time she is impure after she got married because of hymenal bleeding (or beilat mitzvah) could do the hefsek tahara on the fourth day and she doesn't need to wait until the fifth day as long as she stopped seeing blood on or before the fourth day and she didn't see her regular period afterwards. This only applies if they didn't have tashmish during Ben Hashemashot. If she saw her regular period she must wait to do the hefsek tahara on the fifth day from when she started seeing blood.
- A bride before her wedding according to most poskim doesn't need to wait 5 days before doing a hefsek tahara.
- If a woman saw blood on a Monday and if she would do the hefsek tahara on the fifth day her tevilah night would be Friday night and if the Friday night which would have been her tevilah night follows a Yom Tov she may do her hefsek tahara on the fourth day as long as she stopped bleeding by the time of the hefsek tahara. A rav should be consulted.
- The hefsek tahara is a very critical bedika done right before night prior to beginning the count of shiva nekiyim. If a woman didn’t do a hefsek she remains a niddah and can’t begin her count of shiva nekiyim even if days or years passed.
- Even if a woman stops seeing blood after 2 or 3 days she shouldn’t perform the hefsek tahara until the 4th day according to Sephardim or 5th day according to Ashkenazim.
- The bedika for hesfek tahara should be performed after mincha ketana (2.5 halachic hours before sunset) and initially it should be performed as close to sunset as possible.  If it was performed earlier than mincha ketana initially it should be redone after mincha ketana, however, after the fact, the hefsek is valid.
- The bedika for the hefsek tahara must be finished before sunset. If she forgot and didn’t do a bedika before sunset she should ask an Orthodox rabbi what to do.
- If she is going to daven maariv before sunset or if the majority of the community is going to daven maariv before sunset she should do the hefsek tahara before that time. After the fact she could do a bedika afterwards until sunset.
- If she did a bedika before she davened maariv or the community davened maariv and then saw blood she should do a bedika afterwards before sunset.
- Initially, a woman should do a bedika with a moch dachuk and leave it there all of Ben Hashemashot. 
- The moch dachuk should be left inside during the entire length of Ben Hashemashot. For Ashekanazim, a woman should leave it there the amount of time they would wait to end Shabbat after sunset, however, if it is difficult she can take it out earlier. For Sephardim ben hashemashot can be assumed to be 15 minutes.
- If it is very painful or if she’s concerned that doing a moch dachuk will cause bleeding she shouldn’t do the moch dachuk at all since she already did a good bedika before sunset.
Counting the Shiva Nekiyim
- The seven days of shiva nekiyim must be consecutive and if she sees blood even on the last days she must start again. 
- A woman who in the middle of her count thought that she was tameh and stopped counting for some days and then realizes that really she was tahor, some poskim write that the woman needs to begin counting again, however, others argue. A person should consult with their rabbi if this situation arises.
- A woman doesn’t need to verbally count each day of the shiva nekiyim.
- On each day of the shiva nekiyim a woman should do a bedika once in the morning and once in the afternoon before nightfall. 
- After the fact, if a woman checked on days 1 and 7 twice a day, the woman may go to the mikveh the night of the 7th. In general if she missed bedikot she should consult a rabbi.
- After the fact, if a woman only checked once a day and not twice a day, some poskim hold that is sufficient.
- A blind woman can do a bedika and show it to her friend to check that it is clean.
- A deaf person who can speak or a mute who can hear are considered perfectly healthy and can do bedikot for themselves. However, a woman who is deaf mute or one who became deranged needs a healthy woman to perform bedikot for her and help her calculate her vestot.
- A woman who wants to perform more bedikot than are necessary whether she is in her shiva nekiyim or is tahor is praiseworthy. However, if she has a bruise in that area and might bleed, she should not perform extra bedikot. Additionally, she should not perform extra bedikot before and after tashmish as described elsewhere. 
- Ashkenazim are strict about how to treat a ketem (stain) during the first three days of shiva nekiyim, whereas in the last 4 days sometimes a ketem is tahor because we assume that it came from something else. However, a ketem that’s a k’gris or smaller is tahor even in the first three days of shiva nekiyim. If a woman has a bruise in that area that is actively bleeding and stained during the first three days of shiva nekiyim needs to consult a posek. Sephardim treat the ketem the same during the first 3 days as the last 4 days.
Preparing for the Mikveh
- Before going to the mikveh a woman must wash her armpit and concealed areas with water and comb her hair so that the hairs aren't stuck together. Additionally, a woman should wash her whole body and hair in hot water.
- Besides the washing a woman must check herself to be sure that she doesn't have any chasisa on herself before going to the mikveh.
- A woman shouldn't wash her hair before going to the mikveh with cold water or a type of liquid that would make her hair tangled.
- Initially a woman should do her washing immediately prior to going to the mikveh. A proper minhag is that a woman start her washing for the mikveh at the end of the day and continue into the night until she goes to the mikveh.  In cases of extenuating circumstances it is permitted to do the washing before going to the mikveh entirely during the day or entirely at night. In such cases a person should consult a rabbi.
Going to the Mikveh
- A woman who was Tameh as a niddah or zavah stays Tameh forever, even years later, until she goes to the Mikveh.
- If her husband is in town it is a mitzvah for a woman to be tovel on the night when she is able to be tovel and not delay it to another night.
- Some say that a woman shouldn't go to the mikveh if her husband isn't in town because of a concern of danger.
- If the woman's Tevilah night is Friday night or Motzei Shabbat are they certainly permitted to go to the mikveh that night. However, if a woman could have gone to mikveh before Friday night or Motzei Shabbat and she didn't intentionally without a real reason, some poskim hold that she may not go to the mikveh on Friday night. Some are lenient even in such a case to let her go to the mikveh on Friday night. 
- If a woman wasn't able to go to the mikveh before Friday night for some reason that made it impossible for her she is certainly allowed to go to the mikveh on Friday night.
- If a woman is going to the mikveh Friday night she should be careful not to squeeze out her hair.
- A woman recite a bracha on going to the mikveh on Friday night as she would any other night.
- Many defend the practice of going to a mikveh on Friday night even though it is lukewarm. Sephardim should try to avoid going to a warm or lukewarm mikveh at night and instead go during Ben Hashemashot.
- A woman may only go to the mikveh on Friday night if her husband is in town.
Tevilah by Day
- It is forbidden for a woman to go to the mikveh by day whether it is her seventh day of Shiva Nekiyim or even the eighth day or later.
- A bride the day of her wedding can go to the mikveh by day if the Chupah of the wedding is at night. In a pressing circumstance it is permitted to have the Chupah by day as long as the yichud is at night.
- In cases where it is impossible to go to the mikveh during the night such as because of danger, a woman may go to the mikveh during the day on the eighth day of her Shiva Nekiyim but not her seventh day.
- After the fact, even though it is forbidden, if nonetheless a woman went to the mikveh during the day on the seventh or eighth day it is effective. Some say that it isn't effective if she went on the seventh by day. Even in such a case she should not tell her husband that she went to the mikveh and either way it is forbidden for them to be together until the night.
- Halachos of Niddah (Rabbi Eider p. 33)
- The gemara Niddah 42a explains that a woman who emits semen is impure and can't count that day for her Shiva Nekiyim. Tosfot Niddah 33a s.v. roeh concludes that a woman can't begin her hefsek tahara until the fourth day after she began to see blood if she was with her husband right before she started seeing.
- Shulchan Aruch 196:11 rules that a woman who sees blood needs to wait 4 days until she can do her hefsek tahara and on that fourth day she can the hefsek tahara. Also, those 4 days are counted from the last time she was with her husband. However, the Rama YD 196:11 rules like the Trumat Hadeshen who says that a woman who sees blood can only do the hefsek tahara on the fifth day and begin the shiva nekiyim the next day. Also, waiting these days applies whether or not she was with her husband recently or even if he wasn't in town at all. The Rama concludes that this is the Ashkenazic minhag and one shouldn't deviate. Halachos of Niddah (p. 33) concurs.
- Sephardic Minhag: Rav Ovadia Yosef in Taharat Habayit (v. 2, p. 392) rules like Shulchan Aruch. On p. 413, he adds that if a woman knew that she only needed to wait 4 days and was machmir to wait 5, if she wants to change her minhag she needs to do a hatarat nedarim. Ben Ish Chai (Rav Paalim 4:20) maintains that the minhag Baghdad was to wait 5 days and it should be maintained. Orot Hatahara 10:23-4 (Rav Zecharya Ben Shlomo) writes that some Sephardim wait 4 days and some 5 days. He adds that the Yemenites hold that immediately after she stops seeing blood, she should wash that area from shichvat zera if they had tashmish within the last 4 days, and then she could do a hefsek tahara.
- Halachos of Niddah p. 34
- See Halachos of Niddah p. 35 who quotes Rav Moshe Feinstein (Igrot Moshe YD 4:17:20) as holding that if a woman saw blood within 9 minutes after sunset she can begin counting her five days from that day and not the night.
- Shach 196:19 quotes the Maharshal as saying that if she saw after she davened maariv she needs to count her 4 or 5 days from that night. The Shach, however, disagrees that it is acceptable to count from the day. Badei Hashulchan 196:161 and Halachos of Niddah (p. 36) are lenient like the Shach.
- Shach 196:22, Taharat Habayit v. 2 p. 419
- Taz YD 196:5 quoting the Maharal of Prague writes that a bride after beilat mitzvah doesn't have to wait 5 days because the impurity of dam betulim is only rabbinic. However, if they really had tashmish during Ben Hashemashot then she can't do the hefsek tahara until the 5th day after the beilat mitzvah. Igrot Moshe YD 4:17:18 writes that if she sees menstrual blood certainly she needs to wait 5 days and not 4 since that is biblical and not rabbinic.
- Halachos of Niddah p. 47
- Pitchei Teshuva 196:15 quotes the Shlah as saying that it is better to do the hefsek tahara on the fourth day to avoid the issue of separating the washing before the mikveh and the tevilah which occurs when her tevilah is on a Friday night that follows a Yom Tov. Halachos of Niddah p. 45 agrees.
- Mishna Niddah 68a, Rashba (Torat Habayit 23b), Tur and S”A 196:5. See Taharat Habayit v. 2 pp. 229-254 whether the need for the hefsek tahara is biblical or rabbinic. The majority opinion including the Rambam (Isurei Biyah 6:20-3) is that it is biblical unlike the opinion of the Or Zaruah 1:338. Nonetheless, based on the Zichron Yosef YD 9 who presents an argument based on rov that today the hefsek is only rabbinic. The argument is discussed at length in the Taharat Habayit. He concludes that in cases of extreme need where a proper hefsek is impossible one should consult a rabbi whether there is room to consider the leniency that was discussed by the Nodeh Beyehuda YD 59.
- S”A and Rama 196:11. Badei Hashulchan 196:160 says that she shouldn’t do her hefsek tahara on a day earlier than she can begin her shiva nekiyim the night afterwards unless there is a need.
- Taharat Habayit 13:1. Badei Hashulchan 196:17 cites a machloket Raah and Bet Yosef whether the gemara was referring to mincha gedola or ketana. Aruch Hashulchan 196:19 advises doing it within a half hour or hour before sunset.
- Shulchan Aruch YD 196:1
- Badei Hashulchan 196:15
- Rama 196:1, Taharat Habayit 13:1
- Badei Hashulchan 196:13
- Rama 196:1 quoting the Trumat HaDeshen writes that once she davens maariv or the community does it is considered nighttime and she can no longer do a bedika. The Rama also cites the Maharil who argues that for purposes of niddah the night is determined by sunset and not maariv or tosefet shabbat. Badei Hashulchan 196:31 writes that initially one should be strict for the Bach to check before accepting Shabbat and again afterwards right before sunset.
- Rama 196:1, Badei Hashulchan 196:32, Orot Hatahara 10:25
- Badei Hashulchan 196:31
- Orot Hatahara 10:25
- Rama 196:1, Badei Hashulchan 196:33
- Shulchan Aruch YD 196:1, Taharat Habayit 13:1
- Badei Hashulchan 196:21
- Taharat Habayit 13:1. See Taharat Habayit v. 2 p. 261 where he writes that even those who are strict for Rabbenu Tam don’t need to be strict to leave the moch inside during all of shem hashemashot of rabbenu tam.
- Badei Hashulchan 196:21, Taharat Habayit v. 2 p. 261
- Shulchan Aruch YD 196:10, Taharat Habayit v. 2 p. 371
- The Meil Tzedaka (no. 63) writes that a woman must be cognisant of the days of her shiva nekiyim in order for them to count, however, if she thought she was tameh in the middle of her shiva nekiyim and then realizes that she was tahor she is considered tameh and needs to start again. Pitchei Teshuva 196:4 quotes this. Rav Ovadia Yosef in Taharat Habayit p. 338 writes that the majority of poskim argue with the Meil Tzedaka and so in a case of need there’s what to rely on to not follow the Meil Tzedaka.
- Shlah (Shaar Ha'otiyot, Ot Kuf, Kedushat Hazug, no. 377) writes that there is a mitzvah of a woman to verbally count each day of the shiva nekiyim. Radvaz 4:27 (no. 1102) writes that there is no mitzvah for a woman to verbally count the days of her shiva nekiyim. He explains that it is different than sefirat haomer because the mitzvah of counting shiva nekiyim is dependent on whether she wants to purify herself to her husband, however, sefirat haomer is an obligatory mitzvah. Maharam Rotenburg 4:292 agrees that there's no mitzvah for a woman to count verbally. Rav Mordechai Willig (Niddah Shiur 3 on yutorah min 51-2) explained that a person shouldn’t tell his wife to follow the Shlah as we’re certainly not on his level of piety.
- S”A 196:4.
- The Rosh (Niddah 10:5) writes that a woman should do a bedika each day of the shiva nekiyim lechatchila. This is also the opinion of the Rashba (Torat Habayit 24a) and Ramban (Hilchot Niddah 9:23).
- The Mordechai (Niddah no. 737) quoting the Roke’ach (317 s.v. boel) as saying that the women should do a bedika twice a day. The Bet Yosef adds that it seems to be against many rishonim who hold once a day is sufficient. Nonetheless, S”A 196:4 writes that one should check daily twice a day.
- The Tenayim in the Mishna Niddah 68b argue if a woman only checked days 1 and 7 if that works, Rabbi Eliezer says it does, Rabbi Yehoshua and Rabbi Akiva hold that it doesn’t. Rav and Rabbi Chanina in 69a argue whether according to Rabbi Eliezer after the fact if it is enough to just check day 1 or 7 or both are necessary. The Rosh (Niddah 10:5) and Rashba (Torat Habayit 24a) rule like Rav that after the fact day 1 or day 7 works. However, the Smag writes that one should be strict for Rabbi Chanina that even after the fact day 1 and 7 is necessary. The Shulchan Aruch writes that one should be strict for the Smag.
- Sidrei Tahara 196:16. Rav Mordechai Willig (Am Mordechai on Shulchan Aruch p. 125) and in a shiur on yutorah.org (Niddah Shiur 13, min 40-50) is even lenient initially to avoid a woman causing herself to bleed unnecessarily and also because of how difficult it often is to check before nighttime. He added that if one wanted to be strict one should check the 1st and 7th day twice. Also, the one bedika should be done in the morning.
- Shulchan Aruch YD 196:7
- Shulchan Aruch YD 196:8
- Mishna Niddah 13a, Shulchan Aruch YD 196:9
- Badei Hashulchan 196:132-3, Taharat Habayit v. 2 p. 370
- Rama 196:10
- Rama 196:10 is lenient, but the Shach argues. Badei Hashulchan 196:146 is strict unless this bruise will bleed for a long time.
- Shulchan Aruch YD 196:10, Taharat Habayit v. 2 p. 372)
- The gemara Bava Kama 72a records that Ezra Hasofer established ten institutions and one of them was that a woman should wash herself before going to the mikveh. Tosfot Niddah 66b s.v. im cites a dispute between Rabbenu Tam and Rabbenu Shemarya in the name of Rashi about what this institution included. Rabbenu Shemarya held that it included washing the entire body, while Rabbenu Tam held it only included the hair. Tosfot concludes that one should be strict for Rabbenu Shemarya and also such is the practice. The Rosh (Mikvaot no. 37) holds like Rabbenu Tam but says it is a proper practice to wash the entire body. The Rambam (Mikvaot 2:16) also holds that the institution was to wash one's hair before going to the mikveh. The Shach 199:2 concludes that the agreement of the poskim was like Rabbenu Tam nonetheless the proper practice is to wash the entire body.
- The gemara Bava Kama 72a explains that the idea that a women has to check herself before going to the mikveh is a biblical obligation. The Rashba (Torat Habayit 31a), Ran (Shavuot 6a s.v. masrich), and Ramban (cited by Tur 199:1) write explicitly that the obligation to check oneself for a chasisa before going to the mikveh (iyun) is biblical. Shach 199:2 agrees. However, the Bet Yosef 199:6 s.v. lechen suggests that the Tur held checking was only a rabbinic obligation. See the Shaarei Tzion 30 who suggests that this might also be the opinion of a number of rishonim, though he admits that his approach isn't supported by much evidence.
- Gemara Niddah 66b, Shulchan Aruch YD 199:2
- Shulchan Aruch YD 199:3
- Rama YD 199:3
- Gemara Shabbat 64b explains that a Niddah remains tameh until she goes to the mikveh in her proper time. The Rambam Isurei Biyah 4:3 adds that she is a Niddah even years later until she goes to a mikveh. Shulchan Aruch YD 197:1 codifies this.
- Tosfot Yevamot 47b s.v. bemayim discusses the source for the halacha that a Niddah needs to go to a mikveh in order to be tahora. Rav Yehudai Goan explained that the Niddah's tevilah is learned as a fortiori from the fact that the utensils she touches need tevilah. The Ri says that it is the pasuk וְהַדָּוָה בְּנִדָּתָהּ (Vayikra 15:33) as interpreted by the Gemara Shabbat 64b a Niddah remains tameh until she goes to the mikveh in the proper time. The Rabbenu Tam derives this halacha from במי נדה יתחטא (Bamidbar 31:23) as understood by the Gemara Avoda Zara 75b.
- Shulchan Aruch YD 197:2.
- Is it a mitzvah for a woman to go to the mikveh immediately when she is able to become tahora? The gemara Shabbat 121a, Niddah 30a quote a dispute between the tenayim whether there is a mitzvah to go to mikveh immediately when it is possible. Tosfot Niddah 30a s.v. ushma minah tevilah write that Rabbenu Chananel held like the majority opinion in Niddah that going to the mikveh at the first opportunity is a mitzvah. However, Tosfot argue that it couldn't be a mitzvah as we see the practice isn't for a Niddah, Shomeret Yom, or Zavah go to mikveh as soon as is possible.
- Application: One possible practical application is a concept the Smag (Lavin no. 111) mentions that if it is a mitzvah then a woman should go to the mikveh when she can become tahora even if her husband isn't in town.
- Halacha: The Maharil (responsa 196), Maharik responsa 35:3, Shach 197:3, Taz 197:2 in explaining the Rama, and Badei Hashulchan 197:10 in explaining Shulchan Aruch all hold like Tosfot that there is no mitzvah for a woman to go to the mikveh immediately when she is able to become tahora. Nonetheless, the Bet Yosef 197:2 adds that everyone agrees that there is a mitzvah for a woman whose husband is around to go to the mikveh at the first opportunity because of the mitzvah of Onah unless her husband doesn't care. Taz 197:2 and Taharat Habayit v. 2. 445 agree.
- Taharat Habayit v. 2 p. 445 quotes the Shvut Yakov 3:77 that woman wouldn't go to the mikveh if their husbands weren't in town out of a concern for evil spirits and he supports this concern. Torah Lishma 216 in fact argues that there's no real basis for this concern but since people are worried it is good to be careful.
- The Gemara Beitzah 18a states that it is permitted for a Tameh person to go to the mikveh on Shabbat and it doesn't appear as though he is fixing himself since observers will think he is just going to washing himself to cool himself off. The Trumat Hadeshen 255 based on the Mordechai explains that nowadays the Ashkenazic minhag isn't to bathe in cold water on Shabbat at all and therefore, someone who goes to the mikveh does appear to be fixing themselves (metaken) and so it is an issue to go to the mikveh on Friday night. However, this only applies if the woman going to the mikveh is going when it isn't her first chance to go. If it is her first opportunity then for the mitzvah of pru urevu it is permitted for her to go on Friday night.
- Bet Yosef 197:2 argues that it should be permitted just like it was in the days of the gemara and doesn't even quote the Trumat Hadeshen. The Darkei Moshe 197:3 concludes that if the woman couldn't have got to the mikveh for any halachic stringency until Friday night she can go then. Even this stringency he writes only applies in a place where this is the minhag.
- The Taz 197:4 holds that anytime a woman couldn't go to the mikveh before the 7th day because it was impossible she can't go on Friday night. If, however, her husband wasn't in town until Friday afternoon and she didn't go to the mikveh, she can not now go on Friday night as it was possible for her to go earlier. Bach 197:3 similarly is strict even if there's no minhag.
- The Rama 197:2 rules that unless there is a minhag otherwise if a woman didn't go to the mikveh since her husband wasn't in town she is allowed to go to the mikveh on Friday night. Bach 197:3 in understanding the Trumat Hadeshen and the Shach 197:3 agree. The Badei Hashulchan 197:29 quotes that the achronim agreed that our minhag today is to allow women to go to the mikveh Friday night if it was pushed off for any reason, based on the Rama and Shach. Additionally, even if it was pushed for no reason, the Badei Hashulchan writes one could be lenient to go to the mikveh Friday night even though some argue.
- Going to the mikveh on Motzei Shabbat is a separate issue. Based on Rashi's reading of the gemara Niddah 67a it is less than ideal to do the preparations for the mikveh at night on Saturday night and then go to the mikveh as he holds that the preparations should be done by day. To be concerned for the opinion of Rashi, the Maharil (responsa chadashot 96) writes that a woman should go to the mikveh on Motzei Shabbat unless that was her first opportunity. The Rama 197:2 codifies this opinion but adds that it only applies where there is a minhag to be strict about this. Badei Hashulchan 197:38 writes that the consensus of the achronim is to be lenient to allow women to go to the mikveh on Saturday night even if they intentionally pushed off mikveh earlier.
- Taharat Habayit v. 2 p. 452 writes that the Sephardic minhag is like the Bet Yosef who permits going to the mikveh on Friday night even if her tevilah night was earlier.
- Rama 197:2, Taz 197:3 like the Trumat Hadeshen unlike the Bach
- Because of the concern of squeezing water out of hair the Raavad (Baalei Hanefesh Shaar Hatevilah) writes that a woman shouldn't go to the mikveh on Friday night. However, the Bet Yosef 199:6 argues that we shouldn't follow the Raavad against the majority of rishonim. This is also the ruling of Shulchan Aruch YD 199:5. Nonetheless, Taharat Habayit v. 2 p. 452 adds that one must be careful not to squeeze out the hair on Shabbat.
- According to the gemara Shabbat 128a squeezing water out of hair isn't considered sechita (squeezing) that is prohibited on Shabbat. The Rambam Shabbat 9:11 codifies this. The Maggid Mishna Shabbat 9:11 and Bet Yosef 330:1 explain that even though there's no biblical prohibition there still is a rabbinic one. Taharat Habayit v. 2 p. 452 shows that the minority opinion of the Sefer HaEshkol is that there is no rabbinic prohibition either. In any event, the Maadenei Yom Tov (Mikvaot no. 37 fnt. 10) explains that the rabbis didn't prohibit going to the mikveh on Friday night because of this concern of squeezing out hair because of the mitzvah of pru urevu.
- Biur Halacha 323:7 s.v. yimalenu asks how it is permitted to recite the bracha for going to the mikveh on Friday night if it will be clear that the woman is going to the mikveh for a mitzvah and not for just cooling off, which is a problem of appearing like fixing oneself (see Gemara Beitzah 18a). He answers that perhaps since in the action of going into the mikveh itself she doesn't appear to be doing a mitzvah it is permitted to recite the bracha beforehand (Sephardim) or afterwards (Ashkenazim). Nonetheless, he concludes that this is a dispute between Tosfot Yevamot 46b and Rambam. Taharat Habayit v. 2 p. 458 quotes the Kol Gadol 15 who answers that the woman should recite the bracha quietly so that no one can tell she's reciting a bracha.
- Chacham Tzvi 11 holds that it is forbidden to go to the mikveh Friday night if the mikveh is heated but it is permitted if it is just heated enough to remove the chill. Nodeh Beyehuda OC 2:24-5 holds that it is permitted to go into a mikveh even if it is lukewarm. Lastly, the Korban Netanel (Bameh Madlikin 22:100) believes it is permitted even if the warm is warm. Nonetheless, the Mishna Brurah 326:17 proves that there is a prohibition to bathe in lukewarm warm on Shabbat. Taharat Habayit v. 2 p. 460-6 agrees.
- The Mishna Brurah 326:7 writes that there is what to rely on to go to a lukewarm mikveh on Friday night. Shemirat Shabbat Kehilchata (ch. 14 fnt. 14) cites the Divrei Chayim who says that the minhag is that the women go in a warm mikveh on Friday night.
- Taharat Habayit v. 2 p. 452 suggests going to the mikveh during ben hashemashot so as to avoid the prohibition of bathing in hot water on Shabbat. He cites the Bnei Binyamin p. 104 as saying that it was the minhag yerushalayim to go to the mikveh during ben hashemashot. He explains that since it is only a derabbanan prohibition to go to the mikveh during the day it is permitted during ben hashemashot. He concludes that if it isn't possible to go during ben hashemashot she may go at night and not delay her night of tevilah.
- Rama 197:2. Badei Hashulchan 197:23 explains that when her husband is in town it is permitted to go because of the mitzvah of pru urevu but if not then it is forbidden as it appears like she's fixing her status of tumah (metaken). This is based on the Trumat Hadeshen 255. See Madenei Yom Tov (Mikvaot no. 37 fnt. 10).
- The gemara Yoma 6b explains that the biblical law is that a Zavah can go to the mikveh on the seventh day of her Shiva Nekiyim but the Niddah may not go until the night. Nonetheless, Rabbi Yochanan in Gemara Niddah 67b establishes that a woman may not go to mikveh during the day even if it is the eighth day or afterwards so that her daughter doesn't see this and mistakenly learn that it is permitted to go to the mikveh on the seventh day during the day (serach bita). Tosfot 67b s.v. mishum understands that this prohibition applies both to a Niddah and to a Zavah even nowadays after the institution of Rabbi Zeira's chumra.
- The gemara continues to ask why nowadays with the chumra of Rabbi Zeira a woman can't go to mikveh during the seventh day. It answers that the rabbis prohibited it lest the couples is together that day and then she sees blood, retroactively invalidating her tevilah. Tosfot s.v. aval explains that the gemara means that it is forbidden to go to mikveh during the day lest they are together afterwards. Rashi s.v. liydei implies this as well. The Baal Hameor (Baalei Hanefesh Shaar Hatevilah ch. 1 no. 1), however, understands that the gemara means that it is forbidden for them to be together on the seventh day but it is permitted to go to the mikveh. The Ramban (Niddah 67b s.v. ubevaday), Rashba (67b s.v. ubenemukei), and Rambam (according to the Bet Yosef 183 s.v. veyesh) understand the gemara similarly to the Baal Hameor but nonetheless say that because of the prohibition for the couple to be together it is also forbidden for her to go to the mikveh during the day.
- Shulchan Aruch YD 197:3 rules like all of the rishonim besides the baal hameor that it is forbidden for a woman to go to the mikveh nowadays during the day.
- Rama 197:3, Dagul Mirvavah 197:3.
- Badei Hashulchan 197:48 based on Rabbi Akiva Eiger responsa 2:71
- Gemara Niddah 67b, Shulchan Aruch 197:4
- Shulchan Aruch YD 197:5
- Rama YD 197:5, Badei Hashulchan 197:67