Circumcision—the removal of the foreskin of the penis—is performed on all male Jewish children on the eighth day after their birth. It is also performed on male converts to Judaism. The operation is called for in Genesis 17 and is considered the strongest required sign of adherence to Judaism. It is also a powerful symbol of the Covenant of Abraham. As implied by the Talmudic tractate Nedarim 31b, circumcision was originally performed because the foreskin was considered to be a blemish. To attain a state of perfection, the foreskin had to be removed.

During ancient times, some Hellenistic Jews—especially those whose loins would be exposed in the course of athletics or public bathing—had an operation performed to conceal their circumcisions. Later, in order to prevent Jewish men from hiding their circumcisions, rabbis added the requirement that the entire foreskin—not just the end portion—be excised completely. This is known as peri’ah, the laying bare of the glans. At a later period an additional requirement was added, directing the circumciser to apply directing that the circumciser to apply his lips to the penis in order to draw the blood that flowed from the incision. For hygienic reasons, this practice was modified to allow the blood to be drawn through a glass tube.

For a baby boy, the circumcision must take place on the eighth day after birth, unless medical reasons prevent it. Only one exception is allowed to the universal requirement that Jewish infant boys be circumcised. If two previous sons have died as a result of the operation, thereby implying hereditary hemophilia, the third and all subsequent sons are exempted from circumcision. The day of circumcision for an infant boy is considered a time of celebration for the entire community. Customarily, the father of the boy hands his son to the circumciser, who recites appropriate prayers and typically invokes Elijah. The ceremony is often followed by a religious meal of celebration.