rabbi, i want to understand mikveh from the ground up, not just the rules.
1. what is it actually. a gathering of 40 seah of natural water, rain or a spring, not drawn water. why does the Torah insist on that specifically, what is conceptually wrong with drawn water?
2. how is it actually done. the whole body has to be underwater at one time, all hair included, nothing blocking the water from the skin. is one full immersion really enough, and if one is the din, where did the extra dunks come from (3 times, or bracha between dunks)?
3. the blessing. we say asher kidshanu bmitzvosav vtzivanu al hatevilah. what is the mitzvah the bracha is on exactly, and why do many people dunk once, say the bracha, then dunk again, doesnt a bracha on a mitzvah have to come before doing it?
4. the purpose. is it only technical, removing tumah, or is the Torah pointing at something bigger? the Rambam at the end of hilchos mikvaos (11:12) says that even though nothing changed in the body, the one who sets his heart on purity becomes tahor the moment he immerses. is that the kavana we are supposed to have?
5. the ocean and pools. the ocean has no tiles, no filter, no bor, why does it count as a mikveh, just because it is natural water that was never drawn? and your site holds that a clean swimming pool is kosher even for women, while most rabbis say a pool is pasul because the water is drawn. what is the shita behind saying a normal pool works?
6. when do we actually go. after niddah with the seven clean days, for geirus, keilim bought from a non jew. what about erev yom kippur and erev rosh hashana for men, your site says that is minhag not halacha, so where did the minhag come from and how serious is it?
7. today. we are all tamei meis with no parah adumah, so outside niddah and geirus, is mikveh doing anything halachic at all today, or is it all minhag and kavana at this point?
basically, what is the mikveh really doing to a person?
Thank you Rabbi, thank you very much.
A mikveh is not really about washing dirt off the body. Tumah and taharah are spiritual states that the Torah created, and we do not pretend to understand exactly how they work. The Rambam says explicitly at the end of Hilchot Mikvaot that these laws are gezeirot hakatuv, decrees of the Torah whose underlying mechanism is not physical. But he also gives us a beautiful way to understand them: just as a person immerses in water and emerges tahor even though nothing visible changed in his body, a person can immerse himself in the “waters of knowledge” and emerge spiritually renewed.
The Sefer HaChinuch gives an especially beautiful explanation. He says that when a person goes completely under the water, it is as though he returns to the beginning of creation, when the world was covered by water, and then emerges like a new creation. The immersion therefore represents renewal: you went into the water in one state and came out ready to begin again. He also explains why water contained in a vessel is different. A vessel is something man-made, bounded and controlled by us; a mikveh is supposed to resemble the natural waters of creation. Interestingly, the Chinuch also holds that drawn water is valid min haTorah and was disqualified by Chazal, which is the opinion of many Rishonim, although other Rishonim disagree. So mayim she’uvin is certainly not as simple as saying that every drop that ever passed through a pipe is automatically a Torah problem.
Practically, the basic immersion is very simple: the entire body, including all the hair, must be underwater at one time, with nothing that constitutes a chatzitzah blocking the water. One complete immersion is enough. The extra immersions are minhagim. That is also why some Ashkenazi women immerse once, say the berachah, and then immerse again: the first immersion satisfies the concern of making the berachah after entering the water, while the second immersion follows the berachah. The extra immersions are meaningful customs, but they are not the basic din.
The ocean is a mikveh because it is itself a natural body of water. It does not need tiles, a bor, pipes or construction in order to become one. A man-made mikveh is simply our way of recreating the halachic conditions that already exist naturally. I also hold that an ordinary clean swimming pool can in most circumstances qualify, because fixed municipal pipes and a built-in pool are not the kind of portable keli that creates the classical problem of mayim she’uvin. Most rabbis today are much stricter about this, so I do not present that as the standard position, but that is the halachic reasoning behind my view.
Today mikveh still has very real halachic uses: niddah, geirut, and tevilat keilim. Mikveh alone cannot remove tumat met; for that we would need the Parah Adumah, which we do not have today. Men’s immersion before Rosh Hashanah, Yom Kippur, Shabbat or other occasions is generally minhag and preparation for kedushah, not the same kind of obligatory purification. So what is mikveh really doing? We cannot describe the spiritual mechanics, but the Torah’s imagery is very powerful: tumah creates a spiritual blockage, and immersion marks a transition back toward taharah and kedushah. You go beneath the water and emerge renewed.
Read our booklet on Hilchot Niddah (in the Jewish Law Section) for Niddah related questions.