A mikveh is a bath used for the purpose of ritual immersion to achieve ritual purity in Judaism. The traditional rules regarding the construction of a mikveh are based on those specified in regulations laid down in the Torah and in classical rabbinical literature.The text describes how a mikveh must be connected to a natural spring or well of naturally occurring water, and thus can be supplied by rivers and lakes which have natural springs as their source. A cistern filled by rainwater is also permitted to act as a mikveh’s water supply, so long as the water is never...