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
The circumcision consists of three procedures, the first being the cutting of the foreskin. The second is the "priah", or peeling back of the epithelium after the foreskin has been amputated. According to Shaye J. D. Cohen, in Why Aren't Jewish Women Circumcised?: Gender and Covenant in Judaism, pg 25, the Torah only commands circumcision (milah). David Gollaher has written that the rabbis added the procedure of "periah" to discourage men from trying to restore their foreskins: 'Once established, periah was deemed essential to circumcision; if the mohel failed to cut away enough tissue, the operation was deemed insufficient to comply with God's covenant' and 'Depending on the strictness of individual rabbis, boys (or men thought to have been inadequately cut) were subjected to additional operations.' In addition to "milah" (the actual circumcision) and "priah", mentioned above, the Talmud mentions a third step, "metzitzah", or squeezing some blood from the wound.