Subsequently, the woman immerses in a mikvah which is a pool of water in contact with, or drawn from, a natural source of water such as an underground spring, rain water etc. After immersion, called Tevilah, the wife is renewed like a bride to her husband, and martial relations are resumed.
The mikvah must contain a minimum of two hundred gallons of rainwater that was gathered and siphoned into the mikvah pool in accordance with a highly specific set of regulations. In extreme cases where the ecquisition of rainwater is impossible, ice or snow originating from a natural source may be used to till the mikvah. As with the rainwater, an intricate set of laws surrounds its transport and handling. The Mikvah waters are commonly chest high.
The mikvah never was a monthly substitute for a bath or shower. In fact, the Halachah stipulates that one must be scrupulously clean before immersing.
