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.
Circumcision controversies
Classical, Hellenistic, and Roman culture found circumcision to be cruel and repulsive. In the Roman Empire, circumcision was regarded as a barbaric and disgusting custom. The consul Titus Flavius Clemens was condemned to death by the Roman Senate in 95 CE for, according to the Talmud, circumcising himself and converting to Judaism. The emperor Hadrian (117-138) forbade circumcision. Overall, the rite of circumcision was especially execrable in Classical civilization, also because it was the custom to spend an hour a day or so exercising nude in the "gymnasium" and in Roman baths, therefore Jewish men did not want to be seen in public deprived of their foreskins.