Av HaTumah

Part of Judaic series of articles on
Ritual purity in Judaism
Tumah and taharah Mikveh
Purification methods Netilat yadayim Mikveh Red heifer Hefsek taharah Hagalah Tevilat Kelim
Hierarchy Av HaTumah
Miscellaneous Niddah Tzaraath Keri Zav Zavah Midras Tumath eretz Ha'Amim Prohibition of Kohen defilement by the dead

In the realm of tumah and taharah terminology, the term Av HaTumah (father of tumah, or simply Av) is a rabbinic term for a person or object that is in a state of tumah (ritual impurity) to the second degree.

A person or object that is a Av HaTumah has the ability to transfer its tumah to another person or object (usually at a downgraded level of tumah).

There are two types of Av HaTumah, the first being one textually listed in the Torah (D'Oraita), the second being one of rabbinic origin (D'Rabbanan).

Examples

An Av HaTumah is generally a person or object that is listed in the Torah. Common examples of an Av HaTumah include a zav, zavah, niddah, metzorah (leper), and midras.

Purification

A person or object that is under Av HaTumah status can usually be purified by immersion in a mikveh and the elapse of sunset.

An exception to purification eligibility are Terracotta vessels (that cannot be purified until broken).