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.

Why is partially infected skin impure but fully infected skin pure? Mary Douglas’ insight into the polluting power of anomalies helps us make sense of this counterintuitive rule.

The Torah allows the removal of vessels from a house before the priest quarantines it for tzaraʿat, understanding impurity here not as the result of physical reality but of a human declaration. This idea is developed further by the rabbis, who apply it to other areas of Jewish law.

After giving birth to a male, the mother is impure for 7 days, followed by 33 days of purification. However, with a female, the mother is impure for 14 days, followed by 66 days of purification.

Mesopotamian gynecological texts and what we know about women’s post-partum flow are helpful in parsing the unusual Hebrew idiom demei tohorah, literally, “bloods of purity,” used in Leviticus 12 to describe the second stage of postpartum bleeding.

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?

A child’s mother remains impure for forty days after the birth of a boy and eighty days after a girl. A comparison of this procedure with similar ones in Hittite birth rituals suggests that this gender-based differentiation serves as a kind of ritual announcement of the child’s gender.

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?

A look at traditional attempts to make sense of a scribal error; does the LXX have the original version?

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.

Following the purification period after birth, a mother must bring a חטאת –“sin offering,” despite her having committed no obvious sin. This offers us a unique glimpse into the prehistory of the Israelite cult, when apotropaic rituals (used to protect against dangerous forces) like those in other ANE cultures, were the norm.

In reference to the parturient, the Torah speaks of a 33 or 66 day period of דמי טהרה “blood of her purity” as distinguished from a 7 or 14 day period “like menstruation.” What is the difference between these two periods according to Leviticus and how did later groups such as rabbinic Jews, Karaites, Samaritans, and Beta Israel understand it?

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.