In Priestly law, impurity is stripped of its mythic origins in the demonic realm but still retains its dangerous, physical presence, and must be mitigated by specific acts of ritual cleansing and banishing, depending on the type of impurity. Purification from the skin disease tzaraʿat (Leviticus 13–14) offers the starkest example of such a ritual.

Already in the early 2nd millennium B.C.E., people knew that diseases were contagious, and fear of contagion plays a key role in the Torah’s laws regarding the skin ailment, tzaraʿat. What does this mean for understanding other kinds of tum’ah?

Leviticus 15 describes two types of impure bleeding for women: menstruation (niddah), and bleeding that is “not during her menstrual period (zavah).” The Rabbis attempt to define the difference in an abstract manner, and in so doing, elide the two.

Leviticus 15:24 does not declare sex with a menstruating woman to be forbidden, only that it results in temporary impurity. Leviticus 18:19 and 20:18, however, strictly prohibit it. What accounts for these two different approaches?

In Leviticus 15, the laws of niddah are about purity; Lev 18 and 20, however, prohibit sex during menstruation. The rabbis, who inherited both of these texts, create a new, hybrid concept: the prohibition of sex while a woman has the status of menstrual impurity.

A rejoinder to Rabbi Dr. Zev Farber’s “The Purification of a Niddah: The Torah Requirement.”

Despite its lengthy coverage of tzaraat, biblical “leprosy,” the Torah omits discussion of its cause, its infectiousness, and its treatment. Comparison to the Mesopotamian rituals pertaining to a strikingly similar disease, Saḫaršubbû, shows that these omissions were far from accidental.

The Archaeological and Textual Evidence 

When and why washing became immersion: between traditional-rabbinic and scientific-critical approaches to the origin of immersion and the mikveh.

Jewish law requires a menstruant woman to purify herself by immersing in water. A schematic look at Leviticus 15 actually implies this is not a Torah requirement.

Immersing in the Priestly Text: In support of Dr. Rabbi Zev Farber's contention in “The Purification of a Niddah: The Torah Requirement” that the Torah does not require women to immerse after niddah in order to become pure.