A symbol of life with enormous spiritual power.
For most people, the sight of blood evokes an unpleasant response, both emotional and physiological. We have a visceral sense that the presence of blood heralds huge changes, like the beginning or end of life, and we know these are often accompanied by significant pain. In the modern world, we tend to limit our contact with blood. Wounds are efficiently bandaged and camouflaged, menstruation is expertly concealed, animal butchering is clandestine. Entertainment often carries a descriptive warning label so we can decide to opt out of viewing gore, even in cartoon form. People can give birth, even by caesarian, and never see a drop of blood. Our world is remarkably sanitized.
In antiquity, however, regular contact with blood was virtually inevitable. Personal injury and illness were more common, more dangerous and far less concealed. Menstrual products were primitive. Child birth and animal slaughter routinely took place at home. Witnessing, managing and mitigating the flow of blood was an integral part of everyday life.
Though it was more ubiquitous, blood was in no way routine or insignificant in the ancient world. Indeed, its role in ancient Jewish life was undeniably far more complex than in secular modernity or even modern Judaism. In the religious imagination of ancient Judaism, blood was at once sacred and dangerous. It polluted and it purified, gave life and represented the disappearance of the same. Significantly, blood mediated the Jewish relationship with G-d.
Blood Represents Life
The Torah’s core claim about blood appears in Leviticus 17:11: “For the life (nefesh) of the flesh is in its blood…” In the biblical worldview, blood is not merely one bodily fluid among many—it is the animating essence of a living being. This conviction underlies two foundational prohibitions that apply not only to Jews, but to all of humanity: the ban on consuming blood and the ban on murder.
Because blood represents life, consuming it is akin to symbolically consuming a creature’s life-force, which is disrespectful and inhuman. The Torah commands that slaughtered animals must be properly drained of their blood, which is returned to the ground. Consuming the blood of an animal incurs the grave biblical penalty of karet, excision, which entails the discontinuation of one’s family line.
Similarly, the spilling of human blood is treated as a metaphysical rupture. After Cain kills Abel, G-d says to the former, “Your brother’s bloods cry out to Me from the ground.” (Genesis 4:10) Classical commentaries suggest that the plural form of blood hints at the gravity of extinguishing not only one life, but also potential generations that would have issued from the murdered person.
Blood Defiles
Biblical law entails a complicated system of purity and impurity. In a nutshell, both objects and people can contract impurity, which renders them unfit for G-d or the Temple. Impurity is a temporary state, however, and there were processes of purification to render objects and people once again fit for divine service.
Impurity could be imparted through blood. For instance, the blood of childbirth and menstruation both cause a woman to become impure. This one aspect of the purity system that is still practiced in Jewish communities today. A menstruating woman is called a niddah and she is forbidden from sexual contact with her partner until she has undergone purification. Today, that process means counting seven clean days in which no blood is seen and then immersing in a mikveh.
Blood Purifies and Atones
Paradoxically, while blood can in certain circumstances be a source of impurity, it is also a primary ingredient in many rites that restore purity. Most purification rituals require a sacrifice whose blood is offered on the altar, which is essential to reversing the impurity.
Indeed, blood was the primary component in all animal sacrifices—whether the purpose of the sacrifice was purification (as above) or not. In the sacrificial system described in the Book of Leviticus, blood serves as the medium through which atonement is achieved. Leviticus 17:11, quoted above as describing blood as the “life” (nefesh) of an animal, goes on to explain why: “For the life (nefesh) of the flesh is in the blood. I have assigned it to you for making expiation for your lives (nafshoteichem) upon the altar; it is the blood, as life, that effects expiation.” On the altar, the blood of the sacrificed animal, which represents the nefesh (“soul” or “life”) of the animal, stands in for the human nefesh in need of atonement. This is why blood is an essential ingredient not only in some purification rituals, but also in atonement rituals.
When performing sacrifices in the Jerusalem Temple, as described in detail in Tractate Zevachim of the Talmud, priests applied blood to the altars of the Temple and sometimes to the curtain of the sanctuary. The blood functioned like a spiritual solvent or detergent, moving impurities and traces of sin out of the human domain and relocating them to the divine sphere where only G-d could resolve them. These texts describe huge quantities of blood flowing through the Temple, sometimes so much that priests and Israelites literally had to wade through it. It stained the Temple’s white stones, which were whitewashed biannually. This was not dirt in the sense a modern might think of it, but rather a sacred fluid that caused spiritual cleansing even as it stained physical stones.
Blood as Covenantal
Perhaps the most dramatic use of blood appears in covenantal rituals, where it becomes the symbol of G-d’s relationship with the Jewish people. In Genesis, Abraham becomes the first person to undergo a ritual circumcision, and he performs the same on his sons. To this day, Jews circumcise their sons in a ceremony called brit milah—covenant of circumcision—which brings their children into the community of Israel through blood.
A more unusual example of covenantal blood from the Bible occurs when the Israelites are assembled at Sinai. Moses performs a ceremony known as brit dam, the “covenant of blood,” described in Exodus 24. Half the blood of sacrificial animals is dashed on the altar and half sprinkled on the people. The ritual visually expresses the shared commitment: Both parties are marked by the same blood, entering a relationship sealed in life itself.
Blood as Protection
One of the most famous biblical episodes involving blood is the first Passover in Egypt. The Israelites smeared lamb’s blood on their doorposts as a sign for G-d to “pass over” their homes (Exodus 12). Here blood functioned as an apotropaic symbol—a protective boundary in a moment of danger. It marked the home as under divine care.
Blood as a Vehicle of the Sacred
In ancient Judaism, blood is never neutral. It delineates boundaries—between life and death, purity and impurity, Israel and the nations, humans and the divine. It can pollute, and it can purify. It can signal harm, and it can bring protection. These seemingly contradictory qualities arise because blood is imagined as the container of life itself. Anything that contains, releases, transfers or threatens life holds immense religious weight.
Later Jewish thinkers often softened or reinterpreted the centrality of blood in religious life. Physical sacrifices ceased with the destruction of the Temple; prayer and ethical action replaced blood rites as the primary modes of atonement. Yet the symbolism of blood remains deeply embedded in Jewish memory and ritual practice: in Passover storytelling, in the circumcision ceremony, in the seriousness with which Jewish law treats the taking of life. In ancient Judaism, blood was not merely biological; it was theological. It stood at the meeting point of body and soul, human and divine.
Rachel Scheinerman is a contributing writer to My Jewish Learning and Jlife magazine.
