Rambam - Sefer HaMitzvos: Positive Mitzvah 109: Positive Mitzvah 109

Positive Mitzvah 109: Immersing in a Mikveh
Leviticus 15:16 "He shall bathe all his body in water"

Just as the Torah defines the different types of impurity - it also outlines the process for purification.

The Torah describes the purification process, commanding the impure person to immerse himself in a mikveh.

A mikveh is a special pool of water of a specific size.

Its water must come from a natural source, rain or a spring.

In the beginning of the universe, the entire creation emerged from water. After an impure person dips in the mikveh, he rises up as a new creation; purified and prepared to serve HaShem.

To a rabbi and talmudic scholar who asked the Rebbe for a blessing for peace of mind so that he could devote himself to his studies: Peace of mind! Peace of mind! The world is burning! Children go on the streets ignorant of all you have to teach them! And all you can think of is your own piece of mind?!!

From: Bringing Heaven Down to Earth by Tzvi Freeman - tzvif@aol.com