Mikvaot: Difference between revisions

# A mikveh is effective to purify a niddah, zavah, and baal keri but a zav specifically needs to dip in a mayan.<ref>Even though there is an opinion that Rashi Shabbat 65 s.v. vsaver cites that a zavah needs to dip in a mayan and a mikveh is insufficient, Rashi rejects it in several places based on a Tosefta Zavim 3:1. See Rashi Bechorot 58b s.v. mikveh. [http://www.hebrewbooks.org/pdfpager.aspx?req=30774&st=&pgnum=49 Shaarei Teshuva of the Geonim 164] written by Rav Natronai Goan holds that a zavah. Tosefta Megillah 1:11 explicitly holds that a Zavah doesn’t need a mayan. The Ramban Vayikra 15:11 points out that the simple explanation of the pesukim is that a zavah can’t go in a mikveh and needs a mayan but that isn’t the explanation of chazal. Rav Yakov Emden in Yavetz responsa 88 defends the teacher of Rashi by saying we don’t follow the Tosefta. See Aruch Lener Niddah 67a who provides another defense of this approach. Either way, this opinion was rejected by many poskim. Rambam Pirush Mishnayot Mikvaot 5:5 and Rosh ad loc. hold that a zavah doesn’t need a mayan. Bet Yosef YD 200:1 quotes the Rambam Mikveh 1:5, [https://beta.hebrewbooks.org/reader/reader.aspx?sfid=9023#p=73 Rashba (Shaar Hamayim 1)], Tur and Shulchan Aruch YD 200:1 conclude that a zavah is purified by a mikveh. The Bach 200:2 explains that really this opinion is only rabbinic and it is supported by Nedarim 40b. Either way the Bach concludes that it was rejected by all of the poskim.</ref>

# A mikveh requires 40 seah at a minimum. The size of 40 seah is measured by 1 amah x 1 amah x 3 amot.<ref>The Gemara Avoda Zara 75b derives from Torah that a mikveh requires 40 seah at a minimum, which is measured by 1 amah x 1 amah x 3 amot. The same idea is found in Eruvin 4b and [http://www.hebrewbooks.org/pdfpager.aspx?req=14026&st=&pgnum=148 Torat Kohanim Shemini 9]. </ref> A person who goes to the mikveh needs to go in it completely at one time and be completely covered by the water at one time.<ref>Bet Yosef YD 198:1 cites the Sifra Emor 4:7 which derives from the pasuk Vayikra 22:6 that a person is only purified by going to the mikveh if one is completely covered by the water at one time. That is codified by Shulchan Aruch 198:1.</ref>

# The minimal amount of a mikveh theoretically is 332 liters but the practice is to use double or triple that amount.<ref>Rav Chaim Noeh in Shiurei Torah (3:29 p. 257) writes that since there’s a 24 log in a seah, 4 reviyot in a log, and 27 dirham in a reviyit, each of which is 3.2 grams of water in a mikveh of 40 seah there is 24*4*27*3.2*40=331,776 grams = 331.8 liters. He says that since perhaps the water measures of the Rambam are slightly different in other waters he says it is sufficient to add 3% which is another 10 liters, altogether 342 liters is certainly sufficient. However, the minhag is to use double or quadruple that amount.</ref>