Menstruation

Menstruation enters the biblical text under the legal vocabulary of impurity (niddah), not under the modern register of physiology. The Torah treats a woman's monthly discharge as a regular, predictable cause of ritual uncleanness with a fixed seven-day duration; the Prophets carry the image into figurative speech for cast-off idols and a defiled people; the wisdom and Maccabean literature inherit the same purity grammar. The narrative books add the human texture — Sarah's old age, Rachel's quick-witted use of the law to keep her father from her saddlebag.

The Levitical Law

The defining statute is Lev 15:19-30. A woman with a blood discharge is "in her impurity seven days," and the impurity is contagious by contact, by what she lies on, and by what she sits on (Lev 15:19-23). Anyone who touches her bed or her seat must wash clothes, bathe, and remain unclean until evening. The law also covers the irregular case — a discharge "many days not in the time of her impurity" — which extends the impurity for the duration of the flow plus seven clean days, after which the woman brings two turtledoves or two young pigeons to the priest at the door of the tent of meeting, and atonement is made for her "before Yahweh for the discharge of her uncleanness" (Lev 15:25-30).

The purpose clause closes Leviticus 15: "Thus you⁺ will separate the sons of Israel from their uncleanness, that they will not die in their uncleanness, when they defile my tabernacle that is in the midst of them" (Lev 15:31). Menstrual impurity belongs, in other words, to the same logic that drives the Day of Atonement, where the high priest makes atonement for the holy place "because of the uncleannesses of the sons of Israel... that stays with them in the midst of their uncleannesses" (Lev 16:16). The impurity, in this register, is framed as a tabernacle-protection regime rather than as moral guilt.

Intercourse During Menstruation

Two prohibitions extend the law into sexual conduct. Lev 20:18 makes the offense capital: "if a man will plow a menstruating woman; he has made naked her fountain, and she has uncovered the fountain of her blood: and both of them will be cut off from among their people." The same act in Lev 15:24 produces only seven days of contagious impurity; the heightened penalty in Leviticus 20 falls on deliberate, knowing violation. Ezekiel makes restraint at this point a marker of the righteous man: he "has not... come near to a woman in her impurity" (Ezek 18:6), set alongside avoidance of idolatry and adultery in the same verse.

The Manner of Women

The narrative books use a softer idiom: "the manner of women." Of Sarah, the text observes that "Abraham and Sarah were old, [and] well stricken in age; it had ceased to be with Sarah after the manner of women" (Gen 18:11) — a clinical aside that sets up the impossibility of Isaac's birth. Rachel deploys the same expression as a tactical excuse when Laban searches the camp for his stolen talismans: she sits on the camel-saddle that hides them and tells her father, "Don't let my lord be angry that I can't rise up before you; for the manner of women is on me. And he searched, but didn't find the talismans" (Gen 31:35). The phrase functions in both passages as a culturally legible euphemism that closes off further inquiry.

Animal Estrus

Jeremiah extends the vocabulary to animals in a single image. Judah's apostasy is a "wild donkey used to the wilderness, that snuffs up the wind in the desire of her soul; in her occasion who can turn her away? All those who seek her will not weary themselves; in her month they will find her" (Jer 2:24). The parallel between "her occasion" and "her month" supplies the cycle; the male donkeys do not have to chase her — they wait for the predictable time.

Figurative Use

The Prophets convert menstrual impurity into a metaphor of comprehensive defilement. Isaiah commands Judah to throw away its silvered and gilded idols "as a menstrual cloth" — the most contemptible disposable object in the household economy — and to say to it, "Get away from here" (Isa 30:22). Lamentations, after Jerusalem's fall, places the city in the same category: "Jerusalem is among them as an unclean thing" (Lam 1:17). Ezekiel makes the analogy explicit for the exile: "when the house of Israel dwelt in their own land, they defiled it by their way and by their doings: their way before me was as the uncleanness of a woman in her impurity" (Ezek 36:17). The figure presupposes that the audience already understands menstrual impurity as a contagious-but-temporary defilement of the Levitical regime; the prophetic move is to apply that grammar to a whole nation's covenant life.

Wisdom and Second Temple

Sirach reflects on the underlying problem of inherited or contagious uncleanness without naming menstruation directly: "What can be made clean from an unclean thing? And how can that which is true come from a lie?" (Sir 34:4). The same chapter mocks empty ritual: "He who washes after [contact with] a dead body, and touches it again, What profit does he have by his washing?" (Sir 34:30). The Maccabean crisis sharpens the stakes — Antiochus's decree forced Israel "to sacrifice swine's flesh, and unclean beasts" and "let their souls be defiled with all uncleannesses, and detestable things" (1Ma 1:47-48), making the whole purity system, of which menstrual law is one pillar, a target of imperial assault and a line of resistance.