Mikvah is a bath used for the purpose of ritual immersion in Judaism. The word ‘mikvah’, as used in the Hebrew Bible, literally means a ‘collection’ – generally, a collection of water. Several biblical regulations specify that full immersion in water is required to regain ritual purity after ritually impure incidents have occurred.
Most forms of impurity can be nullified through immersion in any natural body of water. However, some of them require ‘living water,’ such as springs or groundwater wells. Living water has the further advantage of being able to purify even while flowing, as opposed to rainwater which must be stationary in order to purify. The mikvah is designed to simplify this requirement, by providing a bathing facility that remains in ritual contact with a natural source of water.