Circumcision
Circumcision is very important to most branches of Judaism, with over 90% of male adherents having the procedure performed as a religious obligation. The basis for its observance is found in the Torah of the Hebrew Bible, in Genesis chapter 17, in which a covenant of circumcision is made with Abraham and his descendants. Jewish circumcision is part of the "brit milah" ritual, to be performed by a specialist ritual circumciser, a "mohel", on the eighth day of a newborn son's life, with certain exceptions for poor health. Jewish law requires that the circumcision leaves the glans bare when the penis is flaccid. Converts to Conservative and Orthodox Judaism must also be circumcised; those who are already circumcised undergo a symbolic circumcision ritual. Circumcision is not required by Judaism for one to be considered Jewish, but some adherents foresee serious negative spiritual consequences if it is neglected.
Religious male circumcision
Subject to overriding medical considerations, the circumcision must take place eight days after the birth of the child, even when this falls on "Shabbat". The child must be medically fit for a circumcision to be performed, and Jewish law prohibits parents having their son circumcised if medical doctors hold that the procedure may unduly threaten the child's health (e.g. because of hemophilia). If by reason of the child's debility or sickness the ceremony is postponed, it cannot take place on "Shabbat".